Modulation of solubility, stability, absorption, metabolism, and pharmacokinetic profile of lipophilic drugs by sterols

ABSTRACT

A formulation for drug delivery, providing enhanced modulation of solubility, stability, absorption, metabolism, and/or pharmacokinetic profile of a lipophilic therapeutic agent by formulation with sterols and/or sterol esters, resulting in higher bioavailability of a therapeutic agent administered to a subject in need of such therapeutic agent. The formulation contains a therapeutic agent and a sterol or sterol ester, and can, optionally, further contain a solubilizer and/or an enhancing agent. Also described are pharmaceutical compositions containing the formulations and methods of making and methods of using the formulations and pharmaceutical compositions. Formulations of the disclosure can be constituted to minimize the synthesis of dihydrotestosterone when the therapeutic agent includes testosterone or testosterone esters.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/983,216, filed Dec. 31, 2010, which application claims the benefit ofpriority of U.S. Provisional Patent Application No. 61/291,769, titled“MODULATION OF SOLUBILITY, STABILITY, ABSORPTION, METABOLISM, ANDPHARMACOKINETIC PROFILE OF LIPOPHILIC DRUGS BY STEROLS” and filed onDec. 31, 2009. The disclosure of the foregoing applications are herebyincorporated herein by reference in their entirety, for all purposes.

FIELD OF THE INVENTION

The present invention relates to formulations for administration of atherapeutic agent, where the formulation contains one or moretherapeutic agents, administered with a sterol and, optionally, asolubilizer and an enhancer, where the formulations provide modulationto one or more of: solubility, stability, absorption, metabolism, andpharmacokinetic profile of the therapeutic agent when administered to asubject. The invention also relates to methods of making and methods ofusing the formulations.

DESCRIPTION OF THE RELATED ART

Drug absorption is the process by which a drug is transported from itssite of administration into the blood, via portal or lymphatic system.Oral drug delivery, as one type of delivery, is advantageous in that itprovides easy administration, can be performed by the patient oranother, is not painful to the patient and involves relatively loweffort. Absorption of a drug administered orally occurs along the entiregastrointestinal (GI) tract, although most drug absorption occurs in thelower GI tract. Such absorption can occur via either of the portal andmesenteric lymphatic routes.

The portal route involves transport of the drug through the portal vein,to the liver. Many drugs are metabolized in the liver. This may resultin a lowered systemic bioavailability of the drug as the drug ismetabolized. This lowering of bioavailability is referred to as the“first pass effect.” In other words, the greater the first pass effect,the smaller the amount of the drug that will reach the systemiccirculation. This results in increased doses of the drug taken orally toachieve desired levels for efficacy. Metabolism of a drug may also occurin the GI tract and contributes to the reduced or variable absorption ofsuch a drug.

The lymphatic system is an extensive drainage network spread throughoutthe body. It shadows the blood circulation system and its functionsinclude the transport of fluid components of blood which have passedinto the interstitial space from the capillaries of the circulationsystem. The intestinal lymphatics also play an essential role inabsorption of products from lipid digestion, e.g., long chain fattyacids and lipid soluble vitamins. If the lymphatic route can beoptimized or selected for drug absorption and absorption via the portalroute reduced, then the first pass effect can correspondingly be reducedor bypassed, improving bioavailability of the drug. The drugs are alsometabolized in the GI tract by enzymes present in the brush-border layeror secreted into the GI tract. The amount of the drug available forabsorption is thus impacted by the susceptibility of the drug to thesemetabolizing enzymes. The access of the enzymes to the drug can bemodulated by using excipients which preferentially shield the drug. Theinventor has discovered that sterols minimize the chemical and enzymaticdegradation of the drugs in the GI tract and hence increase the amountof drug available for absorption. This leads to lower doses oflipophilic drugs and modulating the side effect profile of the effectivedose.

Poor water solubility is a significant obstacle for drug absorption.Approximately 40% of drugs worldwide are insoluble in water andtherefore, are difficult to formulate. Since 1995, 90% of drugs releasedinto the market have limited solubility and/or poor permeability(Conners, R. D., and Elder, E. J., Drug Deliv. Tech. 2004, vol. 4, no.8, pp. 1-11; Giliyar, C., et al., Drug Deliv. Tech. 2006, vol. 6, no. 1,pp. 57-63.). Improving solubility will benefit patients and consumers byrendering previously poorly absorbed compounds more bioavailable andhence more effective for a given dose. First, poor water solubility canlimit the type of formulation available to a bioactive compound. Poorlysoluble drugs may have to be dissolved in oils so that they can beincorporated into a capsule. Second, poorly soluble compounds are likelyto have limited bioavailability because once in the body, they do notremain in solution at the site of action. This results in lowerabsorption and reduced efficacy. To counter this, administration ofhigher doses is often necessary. However, higher doses can potentiallylead to increased side effects.

The science of drug administration therefore requires consideration of anumber of factors in evaluating the absorption of a drug, such as typeand route of transport, the drug's properties including itssusceptibility to degradation/metabolism, the formulation by which thedrug is administered, concentration and amounts of drug, poor watersolubility and any inhibitory factors.

Administration via the intestinal lymphatic system provides advantagessuch as avoidance of hepatic first pass metabolism, and the potential totarget specific diseases states known to spread via the lymphaticsystem, for example certain cancers and HIV.

Various studies have been conducted regarding optimization ofadministration, absorption and bioavailability of drugs.

Most formulation approaches to improve bioavailability of waterinsoluble, highly lipophilic drugs are based on either particle sizereduction technologies (e.g. micronization, nano-particle generation) toincrease drug dissolution rate and/or achieve transient solubilization,or technologies to achieve a sustained solubilization of the drug, suchas complexation, or use of lipid-based delivery systems.

The particle size reduction technologies often fail to overcomebioavailability limitations and result in a large food effect, i.e.,much higher exposure in a fed state than in a fasted state, which canlead to greater sensitivity of the pharmacokinetic profile to the fatcontent of meals and the timing of food administration. Theseconventional dissolution enhancement and transient solubilizationtechnologies do not improve the transport across the unstirred water (orboundary) layer (UWL), which separates the bulk fluid phase of the smallintestine lumen from the brush border membrane of enterocytes. For manypoorly soluble drugs, this transport across the UWL represents thedominant rate-limiting step for drug absorption.

A widely utilized approach to achieve sustained solubilization andovercome poor fasted state bioavailability of lipophilic drugs is toutilize solutions in lipid vehicles containing surfactants thatconstitute a self-emulsifying drug delivery system (SEDDS), to effectspontaneous emulsification upon contact of the lipid with fluids in theGI tract. If microemulsions are formed, these are referred to asself-microemulsifying drug delivery systems (SMEDDS). SEDDS produceopaque, white emulsions with lipid droplet sizes of approximately 100nm, while SMEDDS form transparent microemulsions with droplet size ofless than 50 nm (Gursoy et al., Biomed Pharmacother 2004: 58(3):173-182).

SEDDS and SMEDDS form micelles upon dilution and are well suited forproviding the sustained solubilization in vivo and rapid transportacross the UWL. The advantages of SEDDS/SMEDDS include fast absorption,lower effective dose, less variable absorption, and minimal or absenceof food effects. For example, compared to the crude emulsion)(Sandimmune®, a SMEDDS formulation of CyclosporinA (Neoral®) was shownto enhance fasted state bioavailability, decrease the food effect,increase dose linearity and reduce variability in exposures (Perlman etal., Int J Pharm, 15-22, 2008).

The primary mechanism by which lipid-based drug formulations enhancedrug solubilization within the GI tract are by presentation as asolubilized formulation (thereby avoiding solid-state limitations) andby induced changes to the character of the GI environment such thatsolute-solvent interactions and drug solubility are enhanced.

The presence of food within the GI tract was historically regarded as abarrier to absorption, leading to suggestions that drugs should be takenup on an empty stomach. However, it is currently accepted that theinteraction between food and drugs should be examined on an individualbasis. The character and the magnitude of the effect of food onbioavailability is a function of the drug, the dose, the nature of theformulation, the size and composition of the food, and the temporalrelationship between food ingestion and drug administration. (Wagner, J.G. Hosp. Practice 1977, 12, 119-27; Welling, P. G., Postgrad. Med. 1977,62, 73-82; Melander, A., Wld. Rev. Nutr. Diet. 1984, 43, 34-44; Welling,P. G., Clin. Pharmacokinet. 1984, 9, 404-434; Welling, P. G., PharmacolTher. 1989, 43, 425-44.). The altered postprandial absorption isgenerally a function of the changes associated with conversion from thefasted to fed state. Changes due to (i) secretion of gastric acid andbile and pancreatic fluids, (ii) modification of gastric and intestinalmotility patterns, and (iii) alterations in visceral blood and lymphflow have the most significant impact on absorption. Additionally, thecomposition and amount of the food ingested may have an effect on theabsorption of a drug, for instance a meal containing significant lipidcontent may solubilize a drug to a greater extent than in the fastedstate, thus increasing absorption. Review of the literature by WilliamN. Charman et. al., demonstrates that there is often a physicochemicalbasis to altered bioavailability when drugs are administeredpostprandially (William N. Charman et. al., J. Pharm Sci. 1997, 86,269-82; Porter, C. J. H., et. al., Nat. Rev. Drug Discov., 2007, 6,231-248). Charman et. al. proposed that drug candidates for lymphatictransport should have log P>5 and in addition, a triglyceridesolubility>50 mg/mL. The importance of lipid solubility was illustratedby a comparison of the lymphatic transport of DDT (logP 6.19) withhexachlorobenzene (HCB) (logP 6.53). While both compounds have similarlogP values, the difference in lymphatic transport on administration inoleic acid, 33.5% of the dose in case of DDT and 2.3% with HCB, wasattributed to the 13 fold difference in lipid solubility. A recentpublication presented data which refutes the earlier establishedrequirement of >50 mg/ml triglyceride solubility for enhanced lymphaticabsorption (Natalie L. Trevaskis et. al., Pharm Res. 2010, 27, 878-893).

Drugs which show a strong food effect usually show highly variableinter- and/or intra-subject bioavailability. As a result, active patientcompliance is required to ensure proper drug administration.

Testosterone is one of the most important androgens synthesized in thebody. It is formed mainly in the testicles and in small amounts in theadrenal glands and in women in the ovaries. In males, testosterone isresponsible for the development of the male characteristics duringfetal, neonatal and pubertal maturation and finally for attaining themale phenotype and for androgen-dependent functions (for examplespermatogenesis). Testosterone exerts protein-anabolic action (inmuscles, bones, hematopoiesis, kidneys and liver) (E. Mutschler,“Arzneimittelwirkungen” [Drug Actions], 6th edition, pp. 334-337,Wissenschaftliche Verlagsgesellschaft mbh [publisher], Stuttgart,1991.).

Testosterone products currently on the market utilize oral, parenteral,intramuscular, transdermal, sublingual, and/or buccal routes ofadministration. Testosterone is rapidly metabolized by the liver. Oral,and transdermal administration is particularly challenging becausetestosterone is metabolized by 5-alpha reductase enzyme in the skin orGI brush-border layer to dihydrotestosterone resulting insupraphysiological levels of DHT. The plasma half-life of testosteroneis short, i.e., about 10 to 30 minutes. (Auterhoff, H., et al.,“Lehrbuch der Pharmazeutischen Chemie” [Textbook of PharmaceuticalChemistry], 12th ed., pp. 570-573, Wissenschaftliche Verlagsgesellschaftmbh [publisher], Stuttgart, 1991.) Testosterone is rapidly metabolizedby the liver to DHT and other metabolites. To achieve a physiologicalserum level, oral administration of 400 mg of testosterone is needed (S.G. Johnson, et al., Therapeutic effectiveness of oral testosterone,Lancet 2:1974, 1473-1475).

To prolong the action of testosterone, testosterone esters with varyingchain length (testosterone propionate, testosterone enanthate,testosterone undecanoate, etc.) have been developed for intramuscularinjection as an oily solution or suspension. It is known that in contactwith body fluids these esters will slowly hydrolyze under the action ofesterases thus releasing the pharmacologically active testosterone. Theinfluence of the type of ester on the growth of the capon comb afteri.m. injection has already been described (Meier, R. and Tschopp, E.,Arch. Exptl. Pathol. Pharmacol. 226:1955, 532).

One testosterone undecanoate dosage form presently in clinicaldevelopment in the United States is commercially known as Aveed®(Nebido® outside of the United States) and contains 250 mg/mL oftestosterone undecanoate in castor oil. Administrations of 2, 3 or 4 mLof the formulation (500, 750, 1000 mg TU) by i.m. injection demonstratedirritation at the site of injection, pulmonary oil embolism and/orinjection anaphylactic reactions. Overseas the formulation (1000 mg TUin 4 mL; other ingredients: castor oil and benzyl benzoate) has beenapproved for use in various countries and the recommended administrationregimen is 1000 mg initial administration, an optional second 1000 mgdose as soon as 6 weeks, then 1000 mg every subsequent 10-14 weeks.

Oral preparations of androgens are rare. U.S. Patent Application No.2008/0317844 describes a SEDDS formulation of testosterone palmitate(TP). TP, once absorbed, is slowly hydrolyzed prolonging the circulationof TP and, consequently, T. SEDDS formulations comprising TP have a Thalf-life of about 8-9 hours. By comparison, the half-life of T is about10-30 minutes and that of TU is about 1.5 hours. U.S. Patent ApplicationNo. 2010/0173882 describes delayed release formulations of testosteroneundecanoate (TU) which reduce the C_(max) by 5-15% relative to theC_(max) of an immediate release formulation of Andriol® Testocaps® atthe same dose (U.S. Pat. No. 7,138,389; U.S. Patent ApplicationPublication No. 2009/0075961; U.S. Patent Application Publication No.2008/0305177).

U.S. Patent Application Publication No. 2005/0287203 describes a Castoroil formulation of testosterone undecanoate in a pharmaceuticallyacceptable liquid carrier, characterized in that the liquid carriercomprises at least 50% by weight of Castor oil. The formulation alsocontains a lipophilic surfactant such as Lauroglycol™ 35%. The finalformulation contains 53% w/w of Castor oil, 35% Lauroglycol™, and 12%testosterone undecanoate. This formulation is currently marketed inEurope and more than 86 other countries as Andriol® Testocaps®. Anearlier formulation containing testosterone undecanoate in oleic acid ismarketed under various trade names in different countries, e.g. Andriol®or Restandol®. Andriol®, Restandol® or Andriol® Testocaps® is providedas a soft-gelatin capsule formulation containing 40 mg of TU.

To achieve and maintain acceptable testosterone levels in the blood, 3-4such capsules (Andriol® Testocaps®) should be administered daily. Aregimen involving such a large number of separate administrations is notvery suitable for the practical use of TU as an acceptable hormonereplacement therapy (HRT) product, and even less practical for the useof male contraception. So many separate administrations of the drug giverise to varying serum levels and gastrointestinal side effects. Theseeffects can make long-term replacement therapy difficult (A. M.Matsumoto: Hormonal therapy of male hypogonadism, Endocrinol. Metab.Clin. North Am. 23:1994, 857-875).

Other routes of androgen administration (parenteral, intramuscular,transdermal, nasal, sublingual, buccal, subcutaneous) have been studiedby various research groups (for example, by N. A. Mazer, W. E. Heiber,J. F. Moellmer, A. W. Meikle, J. D. Stringham, S. W. Sanders, K. G.Tolman and W. D. Odell, Enhanced transdermal delivery of testosterone: Anew physiological approach for androgen replacement in hypogonadal men,J. Controll. Rel. 19:1992, 347-362).

Drawbacks of the aforementioned therapies are as follows: 1) thetherapies can have a too short effect on the systemic testosteronelevel, with a rapid decrease in the level shortly after an increaseresulting from an oral administration; 2) the therapies' lack ofindividual time control of the testosterone action (in the case of i.m.injection of testosterone esters) due to the inability to change theconstantly set testosterone level over a long period of time (days toweeks to months); 3) the presence of a significant food effect upon oraladministration; 4) the elevation of DHT levels above physiologicalnormal levels due to the metabolism of testosterone and its esters inorgans with high 5-α-reductase activity and 5) where the therapies arein gel form, they may be hazardous to children or others, e.g., where athird party comes in contact with the skin after topical administration.The FDA has recently issued a black box warning for all testosteronedermal gel products.

In consequence, the art continues to seek improvements in methods ofdrug delivery that achieve modulation of solubility, stability,absorption, metabolism, and/or pharmacokinetic profile of therapeuticagents administered to a subject. In particular, improved formulationsfor oral and parenteral androgen administration are highly desirable.

SUMMARY OF THE INVENTION

The present invention relates to a formulation that achieves modulationof solubility, stability, absorption, metabolism, and/or pharmacokineticprofile of a therapeutic agent when administered to a subject, theformulation comprising: at least one lipophilic, poorly water solubletherapeutic agent and a phytosterol or phytosterol ester. Optionally,the formulation further comprises a solubilizing agent effective forsolubilization of the therapeutic agent and/or an agent for enhancementof the biological absorption and/or metabolic stability of thetherapeutic agent. In one aspect, the invention relates to apharmaceutical composition containing such a formulation for oral,parenteral, intramuscular, transdermal, nasal, sublingual, buccal orsubcutaneous administration.

In another aspect the invention relates to a method of enhancingsolubility of one or more poorly soluble therapeutic agent, comprisingcombining: a) a phytosterol or phytosterol ester; b) a non-sterolsolubilizing agent; and c) at least one lipophilic, poorly water solubletherapeutic agents, in a composition, wherein the composition iseffective to enhance solubility of at least one therapeutic agent, ascompared to the solubility of the same therapeutic agent in the absenceof a) a phytosterol or phytosterol ester and b) a non-sterolsolubilizing agent. Optionally, the composition may further comprise anenhancing agent for enhancement of the biological absorption and/ormetabolic stability of the therapeutic agent.

In a still further aspect, the invention provides a method of enhancingbiological absorption or metabolic stability of one or more poorlysoluble therapeutic agents, the method comprising administering: a) aphytosterol or phytosterol ester; b) a non-sterol solubilizing agent; c)an enhancing agent; and d) at least one lipophilic, poorly water solubletherapeutic agent in a composition, wherein the composition is effectiveto enhance biological absorption or metabolic stability of at least onetherapeutic agent, as compared to correspondingly administeredtherapeutic agent in the absence of a) a phytosterol or phytosterolester, b) a non-sterol solubilizing agent and c) an enhancing agent.

In yet another aspect, the invention provides a method of treating acondition, comprising administering: a) at least one lipophilic, poorlywater soluble therapeutic agent; b) a phytosterol or phytosterol ester;c) a non-sterol solubilizing agent effective for solubilization of theat least one therapeutic agent; and d) an enhancing agent effective toenhance the biological absorption and/or metabolic stability of the atleast one therapeutic agent.

In still another aspect, the invention provides a method for maintainingor controlling physiological levels of testosterone and DHT in a subjectin need of testosterone replacement, the method comprisingadministering: a) one or more therapeutic agents selected fromtestosterone, testosterone esters and combinations thereof, in aformulation selected from immediate release, sustained release, andcombinations thereof; b) a phytosterol or phytosterol ester; c) anon-sterol solubilizing agent effective for solubilization of thetestosterone or testosterone ester; and d) an enhancing agent effectiveto enhance the biological absorption and/or metabolic stability of theone or more therapeutic agents; wherein the method is effective todeliver the one or more therapeutic agents to the subject to achieve inthe subject a testosterone level of about 300 ng/dL to about 1100 ng/dLand a DHT level of about 30 ng/dL to about 300 ng/dL.

Other aspects, features and embodiments of the invention will be morefully apparent from the ensuing disclosure and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flowchart of the process used to obtain formulations of theinvention (Table 20), as described in Example 8.

FIG. 2 shows dissolution curves of testosterone undecanoate Formulations9 (Table 2), 51, 53 and 55 (Table 20), as compared to known preparationsdescribed in Example 1 of US2010/0173882.

FIG. 3 shows dissolution curves of testosterone undecanoate Formulations17 (Table 5), 28 (Table 10), 39 (Table 14), 56, 57 (Table 27) and 58(Table 21).

FIG. 4 shows dissolution curves of testosterone undecanoate fromformulations 59, 60, and 61 (Table 22).

FIG. 5A is a mean PK profile of testosterone undecanoate resulting fromtreatments A through F described in Table 23 dosed to 4 beagle dogsafter eating a high fat meal. FIG. 5B is the mean PK profile oftestosterone for the same treatments A-F.

FIG. 6 shows the mean testosterone concentration in beagle dogs dosedwith 80 mg testosterone undecanoate in Formulations 54 and 52 (Table20). Values are the mean values obtained from a single group of 4 dogs.Phytosterols (400 mg) were co-dosed on both occasions

FIG. 7 shows the mean testosterone and DHT concentration profile in 4beagle dogs dosed with 80 mg testosterone undecanoate in formulation 52(Table 20), with and without 5 mg finasteride. Phytosterols (400 mg)were co-dosed on both occasions.

FIG. 8 shows the mean testosterone and DHT concentration profile in 4beagle dogs dosed with 80 mg testosterone undecanoate in formulation 52(Table 20), with and without 0.5 mg dutasteride. Phytosterols (400 mg)were co-dosed on both occasions.

FIG. 9 shows the mean testosterone concentration profile in three beagledog groups (4 per group) dosed with 80 mg testosterone undecanoate informulation 52 (Table 20) and 400 or 800 mg of phytosterols.

FIG. 10 shows the average testosterone and DHT exposures (ng-h/mL) for astudy of 6 treatments G-L each containing 80 mg TU, as provided inExample 5.

FIG. 11 shows the DHT/T ratios for 4 beagle dogs dosed with threetreatments each containing 80 mg TU, as provided in Example 5. Alltreatments were co-dosed with 400 mg phytosterols.

FIG. 12 shows the predicted average human concentrations of testosteroneand DHT resulting from dosing with Treatments I, K, and L as describedin Table 24.

DETAILED DESCRIPTION OF THE INVENTION, AND PREFERRED EMBODIMENTS THEREOF

The present invention relates to improved formulations and methods(e.g., oral, parenteral, intramuscular, transdermal, nasal, sublingual,buccal and/or subcutaneous) for drug delivery involving modulation ofsolubility, stability, absorption, metabolism, and/or pharmacokineticprofile of the therapeutic agent when administered to a subject in needof such therapeutic agent.

It is noted that as used herein and in the appended claims, the singularforms “a”, “and”, and “the” include plural referents unless the contextclearly dictates otherwise.

Specifically, a formulation or composition of the invention includes acombination of one or more therapeutic agents and a sterol or sterolester, where inclusion of the sterol or sterol ester provides anadditive or synergistic effect with respect to one or more of:solubility, stability, absorption, metabolism, and pharmacokineticprofile of the therapeutic agent. By inclusion of a sterol or sterolester, smaller amounts of a therapeutic agent are required in theformulation, to achieve a desired pharmacokinetic profile of thetherapeutic agent in the subject that is similar to that achieved with alarger amount of therapeutic agent administered without the sterol orsterol ester. In a preferred embodiment the sterol is a phytosterol. Aformulation of the invention further includes a non-sterol solubilizerto further modulate the pharmacokinetic profile of the therapeutic agentupon administration of the formulation.

The formulations described herein contain a therapeutic agent insubstantially solubilized form. The formulations improve thebioavailability and pharmacokinetic profile of the therapeutic agentafter oral, parenteral, intramuscular, transdermal, nasal, sublingual,buccal and/or subcutaneous administration and/or improve patientcompliance through an easily followed dosing regimen.

The invention further provides pharmaceutical compositions containingsuch formulations and methods of making and methods of using suchformulations.

The formulations of the invention are formulations for the oral,parenteral, intramuscular, transdermal, nasal, sublingual, buccal and/orsubcutaneous administration of a therapeutic agent. The therapeuticagent contained in such formulation can be generally lipophilic innature (with a log P greater than 2, wherein P is the intrinsicoctanol:water partition coefficient) and poorly water soluble. “Poorlywater soluble,” as referred to herein, refers to drugs for which thedose is not soluble in 250 mL of aqueous solution across a pH range of1.0 to 7.5. This definition is used in The BiopharmaceuticsClassification System (BCS) Guidance published in 2005 by the US Foodand Drug Administration. “Lipophilic” as used herein refers to atherapeutic agent that is soluble in lipids, such as fats, oils, and thelike. Accordingly, in one embodiment, the invention provides aformulation where a lipid is provided as a solubilizer with thetherapeutic agent, so that the administered therapeutic agent isbioavailable, exhibits desirable pharmacokinetic profile and any effectsof food on the oral bioavailability of the therapeutic agent areminimized. Furthermore, hydrophobic drugs defined herein encompass boththose drugs which are inherently hydrophobic (i.e., having a log P of atleast 2) as well otherwise hydrophobic medicaments that have beenrendered hydrophobic with suitable modification (e.g., by conjugation tofatty acids and/or lipids).

The therapeutic agent herein may also be referred to herein as an“active agent,” “drug” or “pharmacologically active agent.” Theabove-listed terms interchangeably refer to a chemical material orcompound which, when administered to an organism (human or animal), isgenerally bioavailable and induces a desired pharmacologic effect.

Examples of therapeutic agents having the above-describedcharacteristics and therefore capable of administration in formulationsof the invention include, but are not limited to: analgesics,anti-inflammatory agents, anti-helminthics, anti-arrhythmic agents,anti-asthma agents, anti-bacterial agents, anti-viral agents,anti-coagulants, anti-depressants, anti-diabetics, anti-epileptics,anti-fungal agents, anti-gout agents, anti-hypertensive agents,anti-malarials, anti-migraine agents, anti-muscarinic agents,anti-neoplastic agents, immunosuppressants, anti-protozoal agents,anti-thyroid agents, anti-tussives, anxiolytics, sedatives, hypnotics,neuroleptics, β-blockers, cardic inotropic agents, cell adhesioninhibitors, corticosteroids, cytokine receptor activity modulators,diuretics, anti-parkinsonian agents, gastro-intestinal agents, histamineH-receptor antagonists, keratolytics, lipid regulating agents, musclerelaxants, nitrates and other anti-anginal agents, non-steroidanti-asthma agents, nutritional agents, opioid analgesics, sex hormones,stimulants and anti-erectile dysfunction agents.

Additionally, the therapeutic agent may be selected from any agent thatis traditionally used as a medicament and lends itself to beingadministered via oral or parenteral (such as intramuscular, transdermal,nasal, sublingual, buccal and subcutaneous) routes of administration.Such therapeutic agents may be chemotherapeutics; antimycotics; oralcontraceptives, nicotine or nicotine replacement agents, minerals,analgesics, antacids, muscle relaxants, antihistamines, decongestants,anesthetics, antitussives, diuretics, anti-inflammatories, antibiotics,antivirals, psychotherapeutic agents, anti-diabetic agents andcardiovascular agents, nutraceuticals and nutritional supplements.

Additional therapeutic agents for administration via formulations of theinvention include vitamins and co-enzymes including, but not limited to,water or fat soluble vitamins such as thiamin, riboflavin, nicotinicacid, pyridoxine, pantothenic acid, biotin, flavin, choline, inositoland paraminobenzoic acid, carnitine, vitamin C, vitamin D and itsanalogs, vitamin A and the carotenoids, retinoic acid, vitamin E andvitamin K and Coenzyme Q 10.

The therapeutic agent of formulations of the invention may also beselected from botanical bioactive agents, such as: polyphenols,isoflavones, resveratrol, soy isoflavones, grape seed extractpolyphenols, curcumin, policosanols, and epigenin; anti-inflammatoryplant extracts such as aloe vera, echinacea and chamomile hammamelisextracts; anti-psoriatic plant extracts, such as chinese zizipus jujube;astringents plant extracts such as hammamelis; anti bacterial plantextracts such as artemisia, chamomile, and golden seal; immunemodulators such as Echinacea; anti-aging or anti-cancer or anti-photodamage agents; anti-inflammatory agents, such as feverfew parthenolides,rejuvenation agents, carotenoids, beta-carotene, lycopene, astaxanthons,lutein, tocopheryl and retinol.

The therapeutic agent of formulations of the invention may also includecoronary drugs, including vasodilators such as nitroglycerin andisosorbide dinitrate, calcium-antagonists such as verapamile, nifedipineand diltiazem, and cardiac-glycosides such as digoxine. Othertherapeutic agents that can be usefully administered in the broadpractice of the invention include analgesics such as morphine,buprenorphine, etc., and local anaesthetics such as lidocaine, and thelike.

Still further, the therapeutic agent of a formulation of the inventionmay be selected from cholesterol-lowering and triglycerides-loweringdrugs: fenofibrate, lovastatin, simvastatin, pravastatin, fluvastatin,atorvastatin, or cerivastatin; anxiolytics, sedatives and hypnotics:diazepam, nitrazepam, flurazepam, estazolam, flunitrazepam, triazolam,alprazolam, midazolam, temazepam, lormetazepam, brotizolam, clobazam,clonazepam, lorazepam, oxazepam, buspirone, and the like; migrainerelieving agents: sumatriptan, ergotamines and derivatives, and thelike; drugs for combating motion sickness: cinnarizine, anti-histamines,and the like; anti-emetics: ondansetron, tropisetron, granisetrone,metoclopramide, and the like; disulfuram; and vitamin K.

Further examples of therapeutic agents for use in formulations of theinvention include: chemotherapeutic agents, including, but not limitedto: cisplatin (CDDP), procarbazine, mechlorethamine, cyclophosphamide,camptothecin, ifosfamide, melphalan, chlorambucil, bisulfan, nitrosurea,dactinomycin, daunorubicin, doxorubicin, bleomycin, plicomycin,mitomycin, etoposide (VP16), tamoxifen, taxol, transplatinum,5-fluorouracil, vincristin, vinblastin and methotrexate, or any analogor derivative variant thereof; antibiotic drugs: Tetracyclines such astetracycline, doxycycline, oxytetracycline, chloramphenicol etc.;Macrolides such as erythromycin and derivatives, etc.; Antivirals: suchas acyclovir, idoxuridine, tromantadine etc.; Antimycotics: Miconazole,ketoconazole, fluconazole, itraconazole, econazole, terconazole,griseofulvin, and polyenes such as amphotericin B or nystatine etc.Anti-amoebics: Metronidazole, metronidazole benzoate and tinidazoleetc.; Anti-inflammatory drugs: steroids or NSAIDs such as indomethacin,ibuprofen, piroxicam, diclofenac etc.; Anti-allergics: Disodiumcromoglycate etc.; Immunosuppressive agents: cyclosporine etc.;Antimicrobial agents that may be used include, but are not limited to,naficillin, oxacillin, vancomycin, clindamycin, erythromycin,trimethoprim-sulphamethoxazole, rifampin, ciprofloxacin, broad spectrumpenicillin, amoxicillin, gentamicin, ceftriazoxone, cefotaxime,chloramphenicol, clavunate, sulbactam, probenecid, doxycycline,spectinomycin, cefixime, penicillin G, minocycline, β-lactamaseinhibitors; meziocillin, piperacillin, aztreonam, norfloxacin,trimethoprim, ceftazidime, ceftriaxone and dapsone; Antifungal agentsinclude, but are not limited to: ketoconazole, fluconazole, nystatin,itraconazole, clomitrazole, and amphotericin B. Antiviral agents,include, but are not limited to: acyclovir, trifluridine, idoxorudine,foscarnet, ganciclovir, zidovudine, dideoxycytosine, dideoxyinosine,stavudine, famciclovir, didanosine, zalcitabine, rifimantadine, andcytokines. Antihistamines useful for therapeutic administration include,but are not limited to: cimetidine, ranitidine, diphenydramine,prylamine, promethazine, chlorpheniramine, chlorcyclizine, terfenadine,carbinoxamine maleate, clemastine fumarate, diphenhydraminehydrochloride, dimenhydrinate, prilamine maleate, tripelennaminehydrochloride, tripelennamine citrate, chlorpheniramine maleate,brompheniramine maleate, hydroxyzine pamoate, hydroxyzine hydrochloride,cyclizine lactate, cyclizine hydrochloride, meclizine hydrochloride,acrivastine, cetirizine hydrochloride, astemizole, levocabastinehydrochloride, and loratadine. Decongestants and antitussives include,but are not limited to: dextromethorphan, levopropoxyphene napsylate,noscapine, carbetapentane, caramiphen, chlophedianol, pseudoephedrinehydrochloride, diphenhydramine, glaucine, pholcodine, and benzonatate.Other therapeutic agents administerable in formulations of the inventioninclude: anesthetics, such as: etomidate, ketamine, propofol, andbenodiazapines (e.g., chlordiazepoxide, diazepam, clorezepate,halazepam, flurazepam, quazepam, estazolam, triazolam, alprozolm,midazolam, temazepam, oxazepam, lorazepam), benzocaine, dyclonine,bupivacaine, etidocaine, lidocaine, mepivacaine, promoxine, prilocalne,procaine, proparcaine, ropivacaine, and tetracaine. Other useful agentsmay include: amobartital, aprobarbital, butabarbital, butalbitalmephobarbital, methohexital, pentobarbital, phenobarbital, secobarbital,thiopental, paral, chloral hydrate, ethchlorvynol, clutethimide,methprylon, ethinamate, and meprobamate; Analgesics, including, but notlimited to: opioids such as morphine, mepidine, dentanyl, sufentranil,alfentanil, aspirin, acetaminophen, ibuprofen, indomethacine, naproxen,atrin, isocome, midrin, axotal, firinal, phrenilin, ergot and ergotderivatives (wigraine, cafergot, ergostat, ergomar, dihydroergotamine),imitrex; Diuretics including, but not limited to: acetazolamide,dichlorphenamide, methazolamide, furosemide, bumetanide, ethacrynic acidtorseimde, azosemide, muzolimine, piretanide, tripamide,bendroflumethiazide, benzthiazide, chlorothiazide, hydrochlorothiazide,hydroflumethiazide, methyclothiazide, polythiazide, trichlormethiazide,indapamide, metolazone, quinethazone, amiloride, triamterene,sprionolactone, canrenone, and potassium canrenoate; Anti-inflammatoriesincluding, but not limited to: salicylic acid derivatives (e.g. aspirin)paraminophenol derivative (e.g. acetaminophen) indole and indene aceticacids (indomethacin, sulindac and etodalac) heteroaryl acetic acids(tolmetin diclofenac and ketorolac) aryl propionic acid derivatives(ibuprofen, naproxen, ketoprofen, fenopren, oxaprozine), anthranilicacids (mefenamic acid, meclofenamic acid) enolic acids (piroxicam,tenoxicam, phenylbutazone and oxyphenthatrazone); Psychotherapeuticagents including, but not limited to: thorazine, serentil, mellaril,millazine, tindal, permitil, prolixin, trilafon, stelazine, suprazine,taractan, navan, clozaril, haldol, halperon, loxitane, moban, orap,risperdal, alprazolam, chlordiaepoxide, clonezepam, clorezepate,diazepam, halazepam, lorazepam, oxazepam, prazepam, buspirone, elvavil,anafranil, adapin, sinequan, tofranil, surmontil, asendin, norpramin,pertofrane, ludiomil, pamelor, vivactil, prozac, luvox, paxil, zoloft,effexor, serzone, desyrel, nardil, parnate, eldepryl; Cardiovascularagents including, but not limited to: nitroglycerin, isosorbidedinitrate, sodium nitroprisside, captopril, enalapril, enalaprilat,quinapril, lisinopril, ramipril, losartan, aminone, lirinone,vesnerinone, hydralazine, nicorandil, prozasin, doxazosin, bunazosin,tamulosin, yohimbine, propanolol, metoprolol, nadolol, atenolol,timolol, esmolol, pindolol, acebutolol, labetalol, phentolamine,carvedilol, bucindolol, verapamil, nifedipine, amlodipine anddobutamine.

The compositions of the invention, in various embodiments provideeffective formulations for oral, parenteral, intramuscular, transdermal,nasal, sublingual, buccal and/or subcutaneous administration ofandrogens as the therapeutic agent.

Androgens have diverse effects in many tissues. Recent studies havebegun to elucidate the mechanisms of their anabolic effects. Themechanistic understanding is leading to an increase in clinicalusefulness for many disease states. The strongest indication for the useof androgens is for replacement therapy in hypogonadal men to maintainsexual function and libido, muscle strength, and prevent the developmentof osteoporosis. Another use is for the stimulation of erythropoiesis incondition of bone marrow suppression such as aplastic anaemia.

As men age, testosterone concentrations are reduced and considerableinterest has developed over the use of physiologic doses of testosteroneto return concentrations to the level of young men. Testosteroneadministration increases muscle protein synthesis, muscle strength,improve mood and quality of life in older men. There is alsoconsiderable interest in the use of androgens as replacement therapy inpost-menopausal women and the benefits of improvement in musclestrength, sexuality and libido are compelling in this group of women.

Androgens have also shown clinical usefulness in the treatment of musclewasting syndromes. In men with AIDS wasting syndrome, there was a directrelationship between the loss of lean body mass and the degree ofhypogonadism present in the disease. Testosterone replacement in men andwomen with AIDS wasting syndrome increases weight gain in thisdebilitating condition. Androgens have also shown anabolic effects onmuscular dystrophy, metabolic syndrome, and Alzheimer disease (Diab.Nutr. Metab. 12:339-343, 1999).

Androgen-containing formulations are therefore of interest inpreparations for male contraception and male HRT (hormone replacementtherapy). Androgens can also be used in the female, e.g. as androgenreplacement therapy in postmenopausal women. Androgens may particularlybe used as a replacement for or a supplement to endogenous testosterone.Thus, e.g., in male HRT, androgen is administered in order to relievethe undesired effects of the (partial) androgen-deficiency including,but not limited to, effects on bone mineral density, changes in bodycomposition, reduction of sexual interests and erectile dysfunction. Inone embodiment, the invention provides androgen-containing formulationsuseful for administration of androgens to a subject in need of suchadministration.

In one embodiment, the therapeutic agent of a formulation of theinvention may be selected from testosterone and esters thereof.Testosterone esters may include, but are not limited to, any C₁-C₂₄esters of testosterone, including testosterone proprionate, testosteroneenanthate, testosterone cypionate, testosterone undecanoate,testosterone cyclohexylmethylcarbonate, and testosterone triglyceride.Additional testosterone esters can include, but are not limited to,formate, acetate, butyrate, valerate, hexanoate, heptanoate, octanoate,nonanoate, and decanoate. In one embodiment, the therapeutic agent is atestosterone ester with a carbon structure that is linear or branched,and saturated, monounsaturated or polyunsaturated.

As used herein, the identification of a carbon number range, e.g., inC₁-C₁₂ alkyl, is intended to include each of the component carbon numbermoieties within such range, so that each intervening carbon number andany other stated or intervening carbon number value in that statedrange, is encompassed, it being further understood that sub-ranges ofcarbon number within specified carbon number ranges may independently beincluded in smaller carbon number ranges, within the scope of theinvention, and that ranges of carbon numbers specifically excluding acarbon number or numbers are included in the invention, and sub-rangesexcluding either or both of carbon number limits of specified ranges arealso included in the invention. Accordingly, C₁-C₁₂ alkyl is intended toinclude methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl,nonyl, decyl, undecyl and dodecyl, including straight chain as well asbranched groups of such types. It therefore is to be appreciated thatidentification of a carbon number range, e.g., C₁-C₁₂, as broadlyapplicable to a substituent moiety, enables, in specific embodiments ofthe invention, the carbon number range to be further restricted, as asub-group of moieties having a carbon number range within the broaderspecification of the substituent moiety. By way of example, the carbonnumber range e.g., C₁-C₁₂ alkyl, may be more restrictively specified, inparticular embodiments of the invention, to encompass sub-ranges such asC₁-C₄ alkyl, C₂-C₈ alkyl, C₂-C₄ alkyl, C₃-C₅ alkyl, or any othersub-range within the broad carbon number range.

“Alkyls” as used herein include, but are not limited to, methyl, ethyl,propyl, isopropyl, butyl, s-butyl, t-butyl, pentyl and isopentyl and thelike. “Aryls” as used herein includes hydrocarbons derived from benzeneor a benzene derivative that are unsaturated aromatic carbocyclic groupsof from 6 to 10 carbon atoms. The aryls may have a single or multiplerings. The term “aryl” as used herein also includes substituted aryls.Examples include, but are not limited to phenyl, naphthyl, xylene,phenylethane, substituted phenyl, substituted naphthyl, substitutedxylene, substituted phenylethane and the like. “Cycloalkyls” as usedherein include, but are not limited to cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl and the like. In all chemical formulae herein, arange of carbon numbers will be regarded as specifying a sequence ofconsecutive alternative carbon-containing moieties, including allmoieties containing numbers of carbon atoms intermediate the endpointvalues of carbon number in the specific range as well as moietiescontaining numbers of carbon atoms equal to an endpoint value of thespecific range, e.g., C₁-C₆, is inclusive of C₁, C₂, C₃, C₄, C₅ and C₆,and each of such broader ranges may be further limitingly specified withreference to carbon numbers within such ranges, as sub-ranges thereof.Thus, for example, the range C₁-C₆ would be inclusive of and can befurther limited by specification of sub-ranges such as C₁-C₃, C₁-C₄,C₂-C₆, C₄-C₆, etc. within the scope of the broader range.

In a further embodiment of the invention, the therapeutic agent isselected from testosterone and/or testosterone undecanoate (TU). In afurther embodiment, the formulation contains a combination oftestosterone and one or more testosterone esters as therapeutic agents,where the ratio of testosterone to testosterone ester is from about0:100 or 100:0 to about 1:1, preferably from about 1:10 to about 1:3 orfrom about 10:1 to about 3:1. In various other embodiments, the ratio oftestosterone to testosterone ester may be in a range having a lowervalue of any of 0, 0.01, 0.05, 0.1, 0.15, 0.2, 0.33, 0.5, 1.0, 2.0 and3.0 and having an upper value of any of 90.5, 91.0, 91.25, 91.5, 91.75,92.0, 93.0, 94.0, 95.0, 97.5, 99.0, 99.5, 99.75, 99.9, 99.95 and 100.0.In a preferred embodiment, the formulation contains testosterone and/orTU as therapeutic agents.

As used herein, references to the amounts of therapeutic agents aspercent by weight of a formulation may be made as equivalent to T. Forpurposes of such calculations with regard to testosterone esters, it isnoted that 100 mg of T is equivalent to 139 mg testosterone enanthate,158 mg testosterone undecanoate, 143 mg testosterone cypionate, and 183mg testosterone palmitate. Amounts of therapeutic agents included informulations of the invention may be proportionally adjusted, relativeto testosterone.

The invention addresses the problem of providing an orally activeandrogen formulation that is well absorbed in the human body. It hasbeen well established by dog (Shackleford J. Pharmacol. and Exp. Ther.,925-933, 2003) and human studies that testosterone undecanoate isabsorbed almost exclusively via the intestinal lymphatics (Coert et al.,Acta Endocrinol (Copenh), 789-800, 1975; Nieschlag et al., ActaEndocrinol (Copenh), 366-374,1975; Horst et al., Klin Wochenschr,875-879, 1976), thereby bypassing hepatic metabolism. Particularly, theinvention provides SEDDS formulations of testosterone undecanoatecontaining phytosterols which enhances lymphatic absorption of TU byabout 10% to about 300% over current commercial products, Andriol®Testocaps®, and known SEDDS formulations (U.S. Patent Application No.2008/0317844; U.S. Patent Application No. 2010/0173882). The inventionalso provides a formulation of TU and/or testosterone that has a higherstrength than currently known TU formulations. In one embodiment, thecomposition is formulated for parenteral administration. In a furtherembodiment, the parenteral administration is intramuscular. Oneembodiment of the present invention also contemplates a formulation thatreleases the therapeutic agent into the patient's system atphysiologically effective levels, over a period of up to 12 hours.Preferably, the formulation releases the therapeutic agent into thepatient's system at physiologically effective levels over a period of upto 24 hours.

The invention provides embodiments where the formulation is effectivefor any of immediate release of the therapeutic agent, sustained releaseof the therapeutic agent, delayed release of the therapeutic agent,and/or any other modified release of the therapeutic agent. In oneembodiment the invention provides a composition formulated for acombination of immediate and modified release of testosterone and/ortestosterone esters.

The oral administration of hormones such as testosterone or estrogen hasproven challenging. Testosterone is generally administered by oralingestion in a bonded form as testosterone undecanoate,methyltestosterone, or testosterone cyclodextrin complex, to avoid thefirst pass effect. When administered in a regimen of hormone replacementtherapy, it is desired to have sustained release properties, yet theseforms of testosterone must be taken multiple times daily.

It was a general belief that testosterone itself could not beadministered by oral ingestion. According to The Pharmacological Basisof Therapeutics, 10th ed., by Goodman and Gilman, oral administration oftestosterone leads to absorption into the hepatic circulation butresults in rapid metabolism by the liver. Therefore, oral ingestion isineffective in delivering testosterone systemically. However, someresearchers have further investigated oral administration oftestosterone.

Svend Johnsen et al., in the publication entitled “TherapeuticEffectiveness of Oral Testosterone,” (Johnsen et al., Lancet, 1974, 21;2(7895):1473-5) described an oral administration of 200 mg of micronizedtestosterone, with a particle size in the range of 2 to 5 microns, tofour patients with no testicular function. It was found that, for aperiod of about 5 to 7 hours, the total serum testosterone of thepatient was in the range of about 300 to 900 ng/dL. Johnsen et al.recommended 200 mg testosterone administered twice daily. However,Johnsen et al. failed to address improving the pharmacokineticproperties of testosterone in order to administer the dose only once aday.

Marie Føgh et al., in the publication entitled “Serum-TestosteroneDuring Oral Administration of Testosterone in Hypogonadal Men andTranssexual Women,” (Føgh et al., Acta. Endocrinol. (Copenhagen), 1978,87(3):643-9) described an oral administration of 200 mg of micronizedtestosterone twice daily. The two doses provided total serumtestosterone within the normal range for greater than about 12 hours. Asingle 200 mg dose of orally administered testosterone with a particlesize in the range of about 125-400 microns provided a total serumtestosterone in the normal range for from about 5 to 7 hours. In view ofthe large doses required to maintain the desired serum levels oftestosterone, and the possible side effects of such doses, Føgh et al.recommended not administering testosterone orally.

P. R. Daggett et al., in the article entitled “Oral Testosterone, aReappraisal,” (Daggett, et al., Horm Res. 1978, 9(3):121-9) described anoral administration of 200 mg of micronized testosterone twice daily.The dosage provided a double peak effect, with a desired level of serumtestosterone for about 4 hours for each peak. Daggett et al. found thatthe administration of oral testosterone was “unsuitable for routineuse.”

Nieschlag et al., in the publication entitled “Influence of Sex,Testicular Development and Liver Function on the Bioavailability of OralTestosterone,” (Nieschlag et al., Eur. J. Clin. Invest. 1977,7(2):145-7) described orally administering 63 mg of testosterone inarachis oil to hypogonadal men. The serum level of testosterone rose tothe desired level for a period of about 1 to 2 hours. Nieschlag et al.stated that oral testosterone “should be considered with caution, sincehigher testosterone doses would be needed to exceed the developingcapacity of the liver to metabolize testosterone.”

In the context of a general consensus that testosterone cannot beefficaciously orally administered, none of the above referencesdiscusses the possibility of providing sustained release properties orcombining testosterone with a testosterone ester to modulate the releaseprofile.

“Modified release,” as used herein, generally refers to release of adrug that differs from immediate release of the drug under the sameconditions via the same route of administration. Modified release mayinclude each of immediate release, sustained release and delayedrelease. “Sustained release,” as used herein, generally refers torelease of a drug whereby the level of drug available to the patient ismaintained at some level over a desired period of time. A variety ofmethods and formulations are used to provide sustained release of drugs.U.S. Pat. No. 5,567,439, describing methods of sustained release, ishereby incorporated by reference.

In one embodiment of the invention, the desired resulting level of totalserum testosterone in a subject is in the range of from about 300 toabout 1100 ng/dL in a male subject and in the range of from about 30 toabout 110 ng/dL in a female subject. A formulation of the presentinvention, with testosterone or TU as the therapeutic agent delivers thedesired level of serum testosterone for a minimum time period of about 8to about 12 hours. After administration of a formulation of theinvention with testosterone or TU as the therapeutic agent, the desiredlevel of serum testosterone may be maintained for more than 12 hours. Ina further embodiment the desired level of serum testosterone may bemaintained for about 24 hours.

In exemplary formulations of the invention, the formulation is designedfor administration three times a day (tid), two times a day (bid), oronce a day (qd). Administration of a formulation of the invention may beby any regimen that achieves the desired resulting level of total serumtestosterone in the target subject.

The formulation and methods of the present invention provide the abilityto administer testosterone and/or testosterone ester in combination withsterols and/or sterol esters to achieve improved sustained releaseproperties, as described more fully herein. In one embodiment, theadministration is oral delivery. In other embodiments, theadministration is parenteral, transdermal, nasal, sublingual, buccal orsubcutaneous.

While various embodiments herein describe oral delivery of formulationsand pharmaceutical compositions containing the therapeutic agent, it isfurther envisioned that the delivery of the drug is performed by anysuitable delivery mechanism that provides therapeutically effectivelevels of the therapeutic agent. Other delivery routes that arecompatible with the selected therapeutic agent and sterols or sterolesters are also contemplated as within the invention. Accordingly,delivery methods of formulations or pharmaceutical compositionsdescribed herein include, but are not limited to sublingualadministration, buccal administration, parenteral administration,intraperitoneal (i.p.) administration, intravenous (i.v.)administration, intraarterial (i.a.) administration, topicaladministration, transdermal administration, intradermal (i.d.)administration, intramuscular (i.m.) administration, subcutaneous (sc)administration, and nasal administration.

In a further embodiment the invention provides a formulation includingmore than one therapeutic agent. Where a second therapeutic agent isincluded in a formulation of the invention, the weight ratio of theprimary therapeutic agent to the secondary therapeutic agent may bevaried and will depend upon the effective dose of each ingredient. Eachtherapeutic agent contained in the composition or dosage form will bepresent in a therapeutically effective amount.

As described in detail above, the low bioavailability of a therapeuticagent caused by the high first-pass effect in the liver can be reducedby optimizing lymphatic absorption of the therapeutic agent. The presentinvention enables enhancement of the lymphatic absorption oftestosterone esters and/or a combination of testosterone withtestosterone esters, by formulations including sterols. In oneembodiment, the sterols are phytosterols. It is shown herein thatsterols, phytosterols and/or phytosterol esters modulate the solubility,stability, absorption, metabolism and pharmacokinetic profile oftherapeutic agents that are lipophilic.

In another embodiment, the invention provides a formulation for theadministration of a therapeutic agent in which the formulation containsa sterol in addition to the therapeutic agent, to provide desiredproperties of solubility, stability, absorption, metabolism and/orpharmacokinetic profile of the therapeutic agent. In a particularembodiment, the therapeutic agent is selected from testosterone andtestosterone undecanoate.

As used herein, “stability” includes the stability of both theformulation and the therapeutic agent, both prior to administration andafter administration to an individual. An improved stability prior toadministration enables longer shelf life, less protective packaging, orstorage at more aggressive environments. An improved stability afteradministration enables improved pharmacokinetic properties, such ashigher exposure, or longer duration of action.

“Sterols,” as used herein, include all of plant, animal and fungalsterols. The sterols may be pure or may be a mixture of sterols. In oneembodiment, the sterol is cholesterol. In another embodiment, the sterolis a “phytosterol,” a plant sterol or stanol, used herein to refergenerally to plant-derived sterols or plant-derived stanols,phytochemicals that are added to foods, or supplements. Use of the termsterols also includes sterol esters, of any of plant-derived,animal-derived or fungal-derived sterol. “Sterol esters,” as used hereinrefer to plant sterols or stanols that have been esterified by creatingan ester bond between a fatty acid and the sterol or stanol. Fatty acidsused in esterification are plant-derived, animal-derived orfungal-derived. Esterification occurs in intestinal cells and is also anindustrial process. Esterification may make plant sterols and stanolsmore fat-soluble so they are easily incorporated into fat-containingfoods, including margarines and salad dressings. Exemplary sterolsuseful in the invention may include, but are not limited to,phytosterols, cholesterol, beta-sitosterol, and/or sitostanol. CardioAidXF® is a commercially available phytosterol mixture comprising from 40%to 58% by weight of beta-sitosterol; from 20% to 30% by weight ofcampesterol; from 14% to 22% by weight stigmasterol; from 0 to 6% byweight brassicasterol; from 0 to 5% by weight sitostanol; and from 0 to15 mg/g tocopherols.

Prior to the present invention, it was well known that a fed state or afasting state of the subject could severely interfere with the deliveryof a therapeutic agent to that subject. As described above, theinteractions between food and drugs should be individually evaluated.

The pioneering work of Borgstrom et al. (J. Clin Invest; 36:1521-1529,1957) and Carey et al. (Am J Med; 49:590-598, 1970), as well as manyothers, contributed to the finding that the bile acid mixed micelle(BAMM) in the fed state and the bile acid (BA) micelle in the fastedstate constitute the endogenous surfactant system that is responsiblefor the delivery or presentation of extremely lipophilic drugs to theenterocyte brush border region.

Cholesterol with a ClogP (calculated logP) of 12 and a water solubilityof ˜10 ng/mL is efficiently absorbed from the intestine by presentationof cholesterol dissolved in the BAMM droplets to the enterocyte brushborder mucosa with subsequent collisional transfer to the glycocalyx.Many other extremely insoluble and lipophilic compounds are absorbedmore efficiently in the fed state where the BAMM is present. The BAMMsystem is more effective than the BA system because of the highermiceller concentration in the fed as compared to the fasted state. Theplant phytosterols which are present in food have similar ClogP andsolubility but are slightly different in structure of the side chain anddisplace a significant percentage of cholesterol from the BAMM andreduce cholesterol absorption.

Accordingly, the present inventor selected sterols for investigation asproviding a modulating effect on the solubility, stability, absorption,metabolism and/or PK profile of various lipophilic drugs. The modulatingeffect provided by sterols in formulations and methods of the inventionis dependent upon the concentration of the sterols. In a particularembodiment the sterols are phytosterols dissolved in a formulationand/or co-dosed as a solid with a formulation. Since phytosterols arevery lipophilic in nature (logP=12), high concentration of phytosterolssuspended in lipid-based formulations bind strongly to the lipophilicdrugs making the drug insoluble and unavailable for absorption. However,phytosterols dissolved in the lipid-based formulation to saturation(about 1% to about 20%) increase the solubility of the lipophilic drug,and increase bioavailability. (Tables 1-20 and FIGS. 5 and 6).

In food effect studies done to date and guidance issued by regulatoryagencies, the fat content of the diet and its influence on the drugabsorption has been emphasized. No attention has been given to the typesof fat (saturated, monounsaturated, polyunsaturated, etc.) and theamount of cholesterol or plant sterols present in each meal. Thevegetable oils contain a number of sterols that differ from cholesterolby having ethyl or methyl groups or unsaturation in the side chain. Thepredominant ones—sitosterol, stigmasterol, and campesterol—can bepresent in Western diets in amounts almost equal to dietary cholesterol(Miettinen T A, Tilvis R S, Kesäniemi Y A. Am J. Epidemiol. 1990;131:20-31). The most prominent is β-sitosterol, which differs fromcholesterol in that it has an ethyl group at carbon 24 of the sidechain. In the early 1950s it was noted that the addition of sitosterolto the diet of cholesterol-fed chickens or rabbits lowered cholesterollevels in both species and inhibited atherogenesis in the latter (PollakO J, Kritchevsky D. Monogr Atherosclerosis, 1981; 10:1-219). Sitosterolor mixtures of soy sterols were studied extensively ascholesterol-lowering agents between 1950 and 1960 (Lees A M, Mok H Y I,Lees R S, McCluskey M A, Grundy S M. Atherosclerosis, 1977; 28:325-338).The preparations achieved cholesterol lowering of approximately 10%(Vahouny G V, Kritchevsky D. In: Spiller G A, ed. NutritionalPharmacology. New York, N.Y.: Alan R Liss Inc; 1981:31-72.). The mode ofaction appears to involve inhibition of cholesterol absorption, althoughthe plant sterols themselves are absorbed very poorly (Tilvis R S,Miettinen T A. Am J Clin Nutr., 1986; 43:92-97). The mechanism ofinhibition of cholesterol absorption is believed to be throughcrystallization and co-precipitation. Ingestion of 1 g of β-sitosterolreduced absorption of cholesterol by 42% in a meal containing 500 mg ofcholesterol (Mattson F H, Grundy S M, Crouse J R. Am J Clin Nutr., 1982;35:697-700). The decrease in plasma cholesterol is probably due to anincrease in LDL receptor activity. However, the decline in plasmacholesterol is relatively less than the decrease in absorption,presumably because of a compensatory increase in cholesterol synthesis.

In the 1980s it was demonstrated that sitostanol, a 5-α saturatedsitosterol derivative, reduced the intestinal absorption of cholesteroland serum cholesterol more effectively than sitosterol and at dosesbelow those of sitosterol. (Heinemann T, Leiss O, von Bergmann K.,Atherosclerosis, 1986; 61:219-223). In a recent study (Miettinen T A,Puska P, Gylling H, Vanhanen H, Vartiainen E., New. Eng. J. Med., 1995;333:1308-1312) sitostanol was interesterified with margarine, and theresultant product (1.9 to 2.6 g sitosterol per day) exhibited ahypocholesterolemic effect in a population with mild hypercholesteremia.The mean 1-year reduction in plasma cholesterol was 10.2%. Thesitostanol was not absorbed and did not appear to interfere withabsorption of fat-soluble vitamins.

Phytosterols have a long history of safe use in humans. The drugCytellin® was marketed in the United States between 1954 and 1982. Thedosage was 6-18 g/d, with higher dosages recommended for those patientsnot responding to the standard dose. Dosages as high as 45 g/d werereported to be well tolerated without serious side effects (Eli LillyPackage Insert M100 Suspension Cytellin® (Beta and Di-hydrobetasitosterols). A drug product indicated for the reduction ofhypercholesterolemia. Dated 1954.). In the modern era, phytosterols havebeen used as margarine additives since about 1995, with the introductionof stanol esters to the Finnish market, and in 2000 with theintroduction of sterol esters under Novel Foods regulations in the EU.As a requirement for market approval, post-launch monitoring wasconducted in the EU, with no unpredicted side effects reported (Lea L J,Hepburn P A. Safety evaluation of phytosterol esters. Part 9: Results ofa European post-launch monitoring programme. Food Chem. Toxicol., 2006;44:1213-22.). The recommended plant sterol/stanol dosages for margarineand other foods are relatively low compared with that of Cytellin®.Consumption levels of 400 mg twice daily of phytosterols are nowrecommended. (Press release dated Feb. 24, 2003 at World Wide Webaddress:npicenter.com/anm/templates/newsATemp.aspx?articleid=4011&zoneid=3).

The principal (n-3) long-chain polyunsaturated fatty acids (LCPUFA) inmarine oils, eicosapentaneoic acid (EPA; 22:5(n-3)) and docosahexaenoicacid (DHA; 22:6(n-3)), have been shown to possess a wide range ofphysiological effects, from alterations in circulating plasma lipids toeicosanoid and cytokine production. There is considerable evidence tosupport reductions in triglycerides and improvement in circulatingHDL-cholesterol in response to high dosage (1-5 gm/d) (n-3) LCPUFA oilsupplementation.

In a recent clinical study, it was found that combined supplementationof (n-3) LCPUFA (1.4 g/d) as oils with phytosterols (2 g/d) has bothsynergistic and complementary lipid-lowering effects in hyperlipidemicmen and women. The combination of phytosterols and (n-3) LCPUFA has beenshown to reduce plasma total cholesterol by 13.3% and LDL-cholesterol by12.5%. The HDL-cholesterol concentration was increased by (n-3) LCPUFA(7.1%) alone and in combination with phytosterols (8.6%), whereasphytosterol treatment alone had no effect. Plasma triglycerideconcentration was lowered by (n-3) LCPUFA (22.3%) alone and incombination with phytosterols (25.9%), whereas phytosterol treatmentalone had no effect. (Michelle A. Micallef et al., J. Nutr. 138:1086-90, 2008)

Testosterone is implicated as one of the gender-related risk factors forcoronary artery disease in men due to its HDL-C lowering effect. Weeklyadministration of 200 mg TE to male powerlifters decreased HDL-C andapolipoprotein A significantly but total cholesterol, LDL-C ortriglyceride levels were not altered (Zmuda et al, Metabolism 42:446-450, 1993).

In a further embodiment, testosterone and/or testosterone esterformulations of the present invention containing LCPUFA and phytosterolsmay be used to minimize the HDL-C lowering effect observed withcurrently available testosterone and/or testosterone ester productsdelivered via oral, parenteral, intramuscular, transdermal, nasal,sublingual, buccal and/or subcutaneous routes of administration.

In one embodiment, the invention provides a formulation for the oraladministration of a therapeutic agent which contains testosterone,testosterone undecanoate and/or another testosterone ester incombination with a phytosterol, where the phytosterol providesmodulation of one or more of: solubility, stability, absorption,metabolism and pharmacokinetic profile of the testosterone ortestosterone ester. The concentration of the dissolved phytosterol(s)ranges from about 1% to about 30% of the formulation, preferably about2% to about 20% solubilized in the formulation to exhibit the desiredmodulating effect.

In another embodiment, the formulation further comprises LCPUFA, LCPUFAoils, LCPUFA esters, and mixtures thereof in addition to the phytosteroland therapeutic agent.

In yet another embodiment, the formulation further comprisessolubilizers (lipids, surfactants, etc.), and LCPUFA, LCPUFA oils,LCPUFA esters, and mixtures thereof, in addition to the phytosterol andtherapeutic agent.

In one embodiment, the amount of phytosterol and/or phytosterol estersin the formulation is an amount effective to modulate the solubility,stability, metabolism and/or bioavailability to deliver the desired PKprofile for a minimum of about 8 to about 12 hours. In anotherembodiment, the modulation will last longer than 12 hours, preferablyabout 24 hours. This modulative effect is important for hormonereplacement therapies, e.g., in elderly men with partial androgendeficiency (PADAM patients), in that a deficient plasma level oftestosterone can be appropriately corrected.

Another embodiment of a dosing regiment for hormone replacement therapy(HRT) involves administering orally a testosterone and/or testosteroneester formulation to hypogonadal men for a specified duration (1 week to6 months) to achieve normal physiological levels of testosterone (300ng/dL-1100 ng/dL in a male subject), followed by parenteraladministration of a long acting intramuscular product of the presentinvention every (6-12 weeks) for maintenance therapy.

As described in detail above, sustained solubilization is a desirablecharacteristic in formulations for enhancing the bioavailability ofwater insoluble, lipophilic drugs. In one embodiment, the inventionincludes formulations including a therapeutic agent, a sterol and anon-sterol solubilizing agent for solubilization of the therapeuticagent. As such, absorption is not dependent on the dissolution of thetherapeutic agent from the formulation in the patient's gastrointestinaltract, as all or a substantial fraction of the therapeutic agent in theformulation is already solubilized prior to administration to thepatient, increasing the amount of therapeutic agent available forabsorption. In a particular embodiment the therapeutic agent is selectedfrom testosterone and testosterone undecanoate and the sterol is aphytosterol.

A “solubilizer” as referred to herein, may also be referred to as a“solubilizing agent.” The terms are used interchangeably.

Solubilizers included in formulations of the invention are anypharmaceutically acceptable material that has a solubility for TU of atleast about 1 mg per gram of the solubilizer, more preferably at leastabout 40 mg per gram of the solubilizer, and most preferably at leastabout 100 mg per gram of the solubilizer. The solubilizer is preferablypresent in an amount such that a significant fraction of the therapeuticagent is solubilized in the composition and is capable of providing animmediate and therapeutically effective amount of the therapeutic agentto a patient in a readily absorbable form upon administration. In oneembodiment, the therapeutic agent is testosterone undecanoate, whichprovides a therapeutically effective amount of testosterone to apatient. Preferably, the solubilizers of the present invention can alsoincrease the solubilization of TU or any other therapeutic agent whenthe composition contacts an aqueous medium, and particularlygastro-intestinal fluids upon administration of the dosage formcontaining the composition. Thus, the solubilizers as provided hereinimprove the dissolution profile of TU or any other therapeutic agent andthereby the bioavailability of TU or any other therapeutic agent. Invarious embodiments, the solubilizer is a non-sterol solubilizer.

In one embodiment, the solubilizers are selected from triglycerides,diglycerides, monoglycerides, free fatty acids, and fatty acid estersand derivatives thereof, individually or in combination. Examples ofsolubilizers include, but are not limited to, propylene glycoldicaprylate/caprate, caprilic/capric triglyceride,caprylic/capric/linoleic triglyceride, e.g. synthetic medium chaintriglycerides having C₈₋₁₂ fatty acid chains or other derivatized(synthetic) triglycerides of the type known and commercially availableunder Miglyol 810, 812, 818, 829 and 840, linoleic acid, linoleic acidethyl ester, fish oils as free fatty acids, their esterification andtheir transesterification products, e.g., of the type known andcommercially available under EPAX 6000 FA, EPAX 4510 TG, individually orin combination. Additional examples include vegetable oils and C₁₂₋₁₈fatty acid mono-, di- and triglycerides prepared by individual admixingor as transesterification products of vegetable oils (such as soybeanoil, almond oil, sunflower oil, olive oil or corn oil) with glycerol.Particularly preferred lower alcohol fatty acid esters include ethyloleate, ethyl linoleate, ethyl caprylate, ethyl caprate, isopropylmyristate, isopropyl palmitate and mixtures thereof.

In the art of pharmaceutical formulation, vitamin E substances have beenknown for their reducing potential and typically used as antioxidants inpharmaceutical compositions. The inventor has found, however, thatvitamin E substances have unexpected solubilization power towardtestosterone undecanoate and other hydrophobic therapeutic agents.Therefore, in one embodiment, the formulation includes a vitamin Esolubilizer.

The inventor also has surprisingly found that nitrogen-containingsolvents have unexpected solubilization power toward testosteroneundecanoate and other hydrophobic therapeutic agents relative to othercommonly used non-nitrogen containing solvents such as glycerol,propylene glycol, and polyethylene glycols. The nitrogen-containingsolvent solubilizer may be selected from, but is not limited to:dimethylformamide, dimethylacetamide, N-alkylpyrrolidone,N-hydroxyalkylpyrrolidone, N-alkylpiperidone, N-alkylcaprolactam andmixtures thereof wherein alkyl is a C₁₋₁₂ branched or straight chainalkyl. Particularly preferred nitrogen-containing solvents includeN-methyl 2-pyrrolidone, N-ethyl 2-pyrrolidone or a mixture thereof.Alternatively, the nitrogen-containing solvent may be in the form of apolymer such as polyvinylpyrrolidone. In another embodiment, theformulation includes a solubilizer selected from nitrogen-containingsolvents,

In additional research, the inventor has further surprisingly found thatreplacing one or more of the hydroxyl groups of glycerol and propyleneglycol with, for example, a C₂-C₂₄ alkyl ester, results in a propyleneglycol or glycerol fatty acid ester with an unexpectedly highsolubilizing power for testosterone undecanoate. In another embodiment,the formulation includes a solubilizer selected from dehydroxylated,esterified non-nitrogen containing solvents, where the hydroxyl grouphas been replaced with an ester.

Similarly, additional research has yielded other unexpectedly effectivesolubilizers for testosterone undecanoate, including esters ofmonohydric alcohols such as ethanol and ethylene glycols such aspolyethylene glycols, with an organic acid such as acetic acid, fattyacids and citric acids.

Another group of solubilizers for use in formulations of the inventionincludes phospholipids. Solubilizing phospholipids include, but are notlimited to, phosphatidylcholine, phosphatidylethanolamine,phosphatidylserine, phosphatidylinositol, lecithins, lysolecithins,lysophosphatidylcholine, polyethylene glycolatedphospholipids/lysophospholipids, lecithins/lysolecithins and mixturesthereof.

In still another embodiment, a formulation of the invention contains asolubilizer that is a hydrophobic or hydrophilic surfactant that wouldenhance the galenic properties of the therapeutic agent within theformulation. Examples of suitable surfactants include, but are notlimited to: polyoxyethylene-sorbitan-fatty acid esters; e.g., mono- andtri-lauryl, palmityl, stearyl and oleyl esters; e.g., products of thetype known as polysorbates and commercially available under the tradename Tween®; polyoxyethylene fatty acid esters, e.g., polyoxyethylenestearic acid esters of the type known and commercially available underthe trade name Myrj®; polyoxyethylene castor oil derivatives, e.g.,products of the type known and commercially available as Cremophors®.Particularly suitable are polyoxyl 35 castor oil (Cremophor®EL) andpolyoxyl 40 hydrogenated castor oil (Cremophor® RH40); α-tocopherol,α-tocopheryl polyethylene glycol succinate (vitamin E TPGS),α-tocopherol palmitate and α-tocopherol acetate; PEG glyceryl fatty acidesters such as PEG-8 glyceryl caprylate/caprate (commercially known asLabrasol®), PEG-4 glyceryl caprylate/caprate (Labrafac® Hydro WL 1219),PEG-32 glyceryl laurate (Gelucire® 44/14), PEG-6 glyceryl mono oleate(Labrafil® M 1944 CS), PEG-6 glyceryl linoleate (Labrafil® M 2125 CS);propylene glycol mono- and di-fatty acid esters, such as propyleneglycol laurate, propylene glycol caprylate/caprate; alsodiethyleneglycol-monoethylether (DGME), commercially known asTranscutol® (Gattefosse, Westwood, N.J.); sorbitan fatty acid esters,such as the type known and commercially available under the name Span®(e.g., Span 85); polyoxyethylene-polyoxypropylene co-polymers, e.g.,products of the type known and commercially available as Pluronic® orPoloxamer®; glycerol triacetate; and monoglycerides and acetylatedmonoglycerides, e.g., glycerol monodicocoate (Imwitor® 928), glycerolmonocaprylate (Imwitor® 308), and mono- and di-acetylatedmonoglycerides.

As described in detail above, one widely utilized approach to achievesustained solubilization is to utilize formulations within a lipidvehicle containing surfactants that constitute a SEDDS or SMEDDS, toeffect spontaneous emulsification upon contact of the lipid with fluidsin the GI tract.

Hydrophilic-Lipophilic Balance (HLB) is a term used to describe anarbitrary scale from 0 to 40 depicting the Hydrophilic/LipophilicBalance of a surfactant. Products with low HLB are more oil soluble.High HLB represents good water solubility. HLB is a numericallycalculated number based on the surfactants' molecular structure. It isnot a measured parameter.

An optimal surfactant hydrophilic lipophilic balance (HLB) foremulsification was found to be around 10 (Shah, N. H. et. al., Int. J.of Pharmaceutics, 106 (1994) 15-23), which can be achieved using acombination of polar and non-polar surfactants. Polar surfactants withhigh HLB's have been utilized to enable microemulsion formation, whileinclusion of a non-polar surfactant (HLB<8) such as medium chainmono/diglycerides can also improve miscibility with oils. Thesepre-concentrates can be administered in softgels, hardgels, or adsorbedon to inert inorganic or organic polymers to generate free flowingpowders. The powder can be compressed into tablets, filled into hardgelatin capsules or formulated into other oral dosage forms known to theart. Alternatively, the pre-concentrates can be formulated forparenteral, intramuscular, transdermal, nasal, sublingual, buccal andsubcutaneous administration.

As described herein, formulations containing solubilizers enhancebioavailability of the therapeutic agent by their solubilization action.Under fasted conditions, a solubilizing species present in theintestinal contents comprise low concentrations of bile salt,phospholipids and cholesterol derived from fasted biliary output. In theabsence of exogenous lipids the solubilization capacity of the fastedsmall intestine remains low and is correlated with the total bile saltconcentrations rather than reflecting the structure of the individualcolloidal species (Pendersen et al., Pharm Res. 17, 891-894, 2000;Kaukonen et. al., Pharm Res. 21, 245-253, 2004). Following the additionof lipids that are representative of the digestion products ofexogenously derived (from lipid-based formulation or food) lipids, thedrug solubilization capacity increases significantly and is dependent onthe nature of the digestion products (in terms of the fatty-acid chainlength) and the characteristics of the colloidal structures they form.For example, the digestion products of medium-chain triglycerides(C_(8-C12) fatty acids and monoglycerides) are amphiphilic and readilycombine with endogenous bile salt, phosphlipid and cholesterol toprovide highly dispersed, optically clear dispersions (even at high(˜150 mM) lipid loads). The drug solubilization capacity of thesecomposite colloidal species can be up to 50-fold higher than that ofendogenous bile salt, phospholipids and cholesterol species (Kosenna etal., J. Pharm Sci. 93, 332-348, 2004).

However, the solubilization capacity is dependent on lipidconcentration, and the solubility of a range of poorly water-solubledrugs has been shown to be enhanced by less than threefold at lower (<25mM) exogenous lipid levels (Kosenna et al., J. Pharm Sci. 93, 332-348,2004; Kosenna et al., J. Pharm. Sci. 94, 481-492, 2005). By contrast,the phase behavior and solubilization characteristics of the speciesformed on the intercalations of the digestion products of long-chaintriglycerides (which comprise primarily C₁₈ lipids, e.g. palm oil, cornoil, canola oil, soybean oil, olive oil, peanut oil, sesame oil,hydrogenated vegetable oils, hydrogenated soybean oil, etc.) varysignificantly when compared to medium-chain triglycerides (Kosenna etal., J. Pharm. Sci. 94, 481-492, 2005). C₁₈ fatty acids andmonoglycerides are considerably less polar than their C₈ or C₁₂equivalents and turbid systems that contain larger (˜100 nm) vesicularspecies are evident even at low (>2.5 mM) lipid concentrations.Importantly, these vesicular species provide for significantly enhanceddrug solubilization capacities. For example, in the presence of 8.75 mMlong-chain fatty acids and 4.4 mM long-chain monoglycerides(approximately the same mass per mass quantities of lipid that led to aless than a threefold improvement in solubilization capacity formedium-chain lipids) solubilization enhancements of up to 20-fold areapparent (Kosenna et al., J. Pharm Sci. 93, 332-348, 2004; Kosenna etal., J. Pharm. Sci. 94, 481-492, 2005). These solubilizationdifferences, which are based on lipid content, are particularlysignificant in the context of the likely luminal concentration of lipidobtained after oral administration of a lipid-based formulation. Forexample, assuming a lipid dose of 750 mg long-chain triglyceride andcomplete digestion, the maximal luminal concentrations of fatty acid andmonoglyceride (solubilized in micelles) post-digestion are approximately8.5 mM and 4.2 mM, respectively.

In contrast to micronized testosterone compositions, the presentformulations do not require a separate in vivo step for the dissolutionof crystalline testosterone undecanoate since a significant fraction ofTU is already solubilized in the compositions by the includedsolubilizer.

Accordingly, the invention in various embodiments provides a formulationfor administration of a therapeutic agent, including 1) one or morelipophilic, poorly water soluble therapeutic agents, 2) a sterol orester thereof; and 3) a solubilizing agent effective for solubilizationof the therapeutic agent. In a particular embodiment, the therapeuticagent is an androgen, and in a more particular embodiment, the androgenis selected from testosterone and testosterone esters, such astestosterone undecanoate. In a preferred embodiment the sterol or esterthereof is a phytosterol. In another embodiment the solubilizing agentis a non-sterol solubilizing agent.

In another embodiment the invention provides a method of enhancingsolubility of one or more poorly water soluble therapeutic agents,including combining 1) a phytosterol or phytosterol ester, 2) anon-sterol solubilizing agent effective for solubilization of thetherapeutic agent, and 3) at least one lipophilic, poorly water solubletherapeutic agent, to form a composition, wherein the composition iseffective to enhance solubility of the at least one therapeutic agent,as compared to the solubility of the same therapeutic agent in theabsence of 1) a phytosterol or phytosterol ester and 2) a non-sterolsolubilizing agent effective for solubilization.

In other embodiments of the present invention, methods and compositionsfor enhancing the absorption and metabolic stability of testosterone ortestosterone undecanoate by incorporating components that maybiochemically modulate (1) T or TU absorption, (2) T or TU metabolism,and/or (3) metabolism of TU to DHTU. For example, TU is absorbed almostexclusively via the intestinal lymphatics (Coert et al., Acta Endocrinol(Copenh), 789-800, 1975; Nieschlag et al., Acta Endocrinol (Copenh),366-374, 1975; Horst et al., Klin Wochenschr, 875-879, 1976; ShacklefordJ. Pharmacol. and Exp. Ther., 925-933, 2003) thereby bypassing hepaticmetabolism. Formulations containing oleic acid, glycerol monooleate,Polyoxyl 40 Hydrogenated Castor Oil (e.g., Cremophore RH 40),Polysorbate 80 (e.g., Tween 80), and phytosterols (Formulation #54)enhance lymphatic absorption relative to the Castor oil and Lauroylglycol (Andriol Testocap®) formulation by 294%. Cremophore RH 40, Tween80, and Solutol HS 15 are known PgP efflux and P450 inhibitors. Tween 80is also a known chylomicron secretion inducer. By using appropriateratios of Cremophore RH 40, and Tween 80, metabolic stability andlymphatic absorption of TU can be enhanced to achieve the desired PKprofile. In one embodiment the formulation contains Polyoxyl 40Hydrogenated Castor Oil (e.g., Cremophore RH 40) and Polysorbate 80(e.g., Tween 80) in a ratio of about 1:10 to about 10:1, more preferablyabout 1:2 to about 2:1.

Other components that can enhance TU absorption and metabolic stabilityinclude natural (e.g., phytosterols, borage oil, gamma-linoleic acid)and synthetic inhibitors (e.g., MK386) of 5-alpha-reductase absorbed viaintestinal lymphatics. 5-alpha-reductase inhibitors such as Finasterideand Dutasteride have minimal effect on modulation of T or DHT exposurefrom oral T or T esters (Table 24) as they are absorbed via the portalvein.

The invention further provides a formulation for oral administration ofa therapeutic agent, including 1) one or more lipophilic, poorly watersoluble therapeutic agents, 2) a sterol or ester thereof; 3) asolubilizing agent effective for solubilization of the therapeuticagent; and 4) an enhancing agent. In a particular embodiment, thetherapeutic agent is an androgen, and in a more particular embodiment,the androgen is selected from testosterone and testosterone esters, suchas testosterone undecanoate. In a preferred embodiment the sterol orester thereof is a phytosterol. In another embodiment the solubilizingagent is a non-sterol solubilizing agent. In a further embodiment theformulation comprises an enhancing agent. In a particular embodiment theenhancing agent is selected from the group consisting of: an inhibitorof 5-α-reductase enzymes, a P450 inhibitor, a PgP inhibitor and achylomicron secretion inducer. In a further embodiment the 5-α-reductaseinhibitor is MK-386, phytosterols, borage oil, or gamma-linoleic acid;the P450 and/or PgP inhibitors are selected from peppermint oil,Cremophore RH 40, Tween-80, and Solutol HS 15; and the chylomicronsecretion inducer is Tween 80.

In another embodiment the invention provides a method of enhancingbiological absorption and/or metabolic stability of one or more poorlywater soluble therapeutic agents, including administering: 1) a sterolor ester thereof; 2) a non-sterol solubilizing agent effective forsolubilization of the therapeutic agent; 3) an enhancing agent effectiveto improve the biological absorption and/or metabolic stability of atleast one therapeutic agent; and 4) at least one lipophilic, poorlywater soluble therapeutic agent, to form a composition, wherein thecomposition is effective to enhance biological absorption and/ormetabolic stability of at least one therapeutic agent, as compared tocorrespondingly administered therapeutic in the absence of 1) a sterolor ester thereof; 2) a non-sterol solubilizing agent; and 3) anenhancing agent.

In a further embodiment the invention provides a formulation consistingessentially of a therapeutic agent and an enhancing agent effective toimprove the biological absorption and/or metabolic stability of thetherapeutic agent. In a particular embodiment the enhancing agent isselected from Cremophore RH 40, Tween-80, phytosterols and phytosterolesters.

The formulations of the invention make use of the advantages of oraladministration of androgens, especially of testosterone and the estersthereof, by exploiting the different pharmacokinetics of the varioustestosterone esters in combination with phytosterols and/or phytosterolesters, so as to be able, by careful selection of appropriate dosagesand esters, to attain a desired drug profile. Particularly, theinvention is advantageous for administration of androgens having highfirst-pass effect and low bioavailability. Formulations of the inventionmay include further additives to achieve a cumulative or additionaltherapeutic effect.

Examples of such further additives may include, but are not limited tolipids, bile salts, 5-α-reductase inhibitors and any other additiveseffective in increasing the bioavailability of the therapeutic agent,maximizing absorption of the therapeutic agent, treating additionalconditions and/or reducing side effects of drug administration, e.g.inflammation. Classes of additives that may be present in thecompositions, include, but are not limited to, absorbents, acids,adjuvants, anticaking agent, glidants, antitacking agents, antifoamers,anticoagulants, antimicrobials, antioxidants, antiphlogistics,astringents, antiseptics, bases, binders, chelating agents,sequestrants, coagulants, coating agents, colorants, dyes, pigments,compatiblizers, complexing agents, softeners, crystal growth regulators,denaturants, dessicants, drying agents, dehydrating agents, diluents,dispersants, emollients, emulsifiers, encapsulants, enzymes, fillers,extenders, flavor masking agents, flavorants, fragrances, gellingagents, hardeners, stiffening agents, humectants, lubricants,moisturizers, bufferants, pH control agents, plasticizers, soothingagents, demulcents, retarding agents, spreading agents, stabilizers,suspending agents, sweeteners, disintegrants, thickening agents,consistency regulators, surfactants, opacifiers, polymers,preservatives, antigellants, rheology control agents, UV absorbers,tonicifiers and viscomodulators. The formulation may include one or moreadditives.

Examples of lipids that may be included as additives to a basicformulation of the invention include, but are not limited to essentialfatty acids. Essential Fatty Acids (EFAs) are necessary fats that humanscannot synthesize, and must be obtained through diet. EFAs arelong-chain polyunsaturated fatty acids derived from linolenic, linoleic,and oleic acids. There are two families of EFAs: omega-3 and omega-6.Omega-9 is necessary yet “non-essential” because the body canmanufacture a modest amount on its own, provided essential EFAs arepresent. The number following the “omega-” prefix represents theposition of the first double bond, counting from the terminal methylgroup on the molecule. Omega-3 fatty acids are derived from linolenicacid, omega-6 from linoleic acid, and omega-9 from oleic acid.

Alpha linolenic acid (ALA) is the principal omega-3 fatty acid, which ahealthy human will convert into eicosapentaenoic acid (EPA), and laterinto docosahexaenoic acid (DHA). EPA and the gamma linolenic acid (GLA)synthesized from linoleic (omega-6) acid are later converted intohormone-like compounds known as eicosanoids, which aid in many bodilyfunctions including vital organ function and intracellular activity.Linoleic acid is the primary omega-6 fatty acid. A healthy human withgood nutrition will convert linoleic acid into GLA.

Therefore, in another embodiment, the formulation further includes oneor more triglycerides containing fatty acids, including, but not limitedto, omega-3, omega-6 and omega-9.

It is known that oral TU treatment elevates dihydrotestosterone (DHT),which may be associated with an increased risk of acne, male patternbaldness and prostate hyperplasia. Co-administration of a 5-α-reductaseinhibitor, such as Finasteride or Dutasteride has been shown to preventreduction of testosterone to DHT. Commercial preparations of Finasterideand Dutasteride are known, e.g. Proscar®, Propecia®, and Avodart®.

The present inventor observed that when 5-α-reductase inhibitorsFinasteride and Dutasteride are first dosed for 3 days in dogs tocompletely inhibit the 5-α-reductase enzyme known to reduce testosteroneto DHT, followed by co-dosing with TU and Finasteride or Dutasteride,there was no significant change in the testosterone or DHT levels. Thisis contrary to published reports and patents issued claiming thatFinasteride and Dutasteride inhibit conversion of testosterone ortestosterone esters to DHT (Amory & Bremner, J Clin Endocrinol Metab,2610-2617, 2005; Amory et al., J Androl, 72-78, 2006; U.S. Pat. No.7,138,389; U.S. Patent Application No. 2008/0317844). TU is absorbedalmost exclusively via the intestinal lymphatics (Coert et al., ActaEndocrinol (Copenh), 789-800, 1975; Nieschlag et al., Acta Endocrinol(Copenh), 366-374, 1975; Horst et al., Klin Wochenschr, 875-879, 1976;Shackleford J. Pharmacol. and Exp. Ther., 925-933, 2003), therebybypassing hepatic metabolism. For reasons of the dependence on lymphaticabsorption, oral TU must be ingested with a meal containing some fat toallow for its optimal absorption and the attainment of serumtestosterone concentrations within the normal range of adult men(Houwing et al., Pharmacotherapy, 1257-1265, 2003; Schnabel et al., ClinEndocrinol, 579-585, 2007). Once TU is absorbed into the intestinallymphatics, a portion of TU is acted upon by 5-α-reductase to formdihydrotestosterone undecanoate (DHTU) (Horst et al., Klin Wochenschr,875-879, 1976). After the TU and DHTU are released into circulation,non-specific plasma esterases enzymatically cleave the undecanoate esterresulting in the liberation of testosterone and DHT in the serum (FIGS.7 and 8). The dog study demonstrates that the pharmacokinetics of orallydosed TU is not improved by the concomitant administration of the5-α-reductase inhibitor Finasteride or Dutasteride. This finding is insharp contrast to published work demonstrating that the concomitantadministration of either Finasteride or Dutasteride significantlyincreased serum testosterone concentrations and significantly suppressedserum DHT concentrations when used in combination with oral testosteronein oil (Amory & Bremner, J Clin Endocrinol Metab, 2610-2617, 2005; Amoryet al., J Androl, 72-78, 2006).

It therefore appears that oral TU is absorbed via intestinal lymphatics(Coert et al., Acta Endocrinol (Copenh), 789-800, 1975; Nieschlag etal., Acta Endocrinol (Copenh), 366-374, 1975), whereas the oralformulations of non-esterified testosterone are absorbed via the portalcirculation (Amory & Bremner, J Clin Endocrinol Metab, 2610-2617, 2005).Finasteride and Dutesteride are also absorbed via the portal circulation(Carlin et al., Drug Metabol Dispos, 148-155, 1992; Branson et al., J.pharmacol & Exp Ther, 1496-1502, 1997), and their absorption is notthought to be affected by food (Steiner et al., Clin Pharmacokinet,16-27, 1996). Therefore, Finasteride and Dutasteride may not be able toprevent the 5-α-reduction of the oral TU because of the different routesof absorption and appearance in the systemic circulation. Consistentwith this hypothesis is the work of Horst et al., Klin Wochenschr,875-879 (1976), that demonstrated the presence of significant amounts ofDHTU in the thoracic ducts of men dosed orally with TU while theirthoracic ducts were cannulated during neck surgery. In connection withthis hypothesism the inventor theorized that 5-α-reductase inhibitorswith proven absorption via the intestinal lymphatics, such as MK-386(Gloria et al., Int. J. of Pharmaceutics, 37-44, 1998), may besuccessful in suppressing the elevations in serum DHT observed withdosing of oral TU.

As will be recognized by those skilled in the art, the amount orpercentage of the therapeutic agent present in the formulation anddosage forms will vary. Thus, for example, the amount of therapeuticagent is based, in part, upon the actual need of the patient and can bedetermined by the attending clinician. In all cases, however, the amountof the therapeutic agent present in the composition and dosage forms isan amount such that the therapeutic agent is significantly solubilizedin the appropriately selected solubilizer or solubilizers so that theaforementioned advantages of the present invention are achieved. In aparticular embodiment the amount or percentage of all elements of aformulation of the invention are optimized to achieve a desired level oftotal serum testosterone in a subject in the range of from about 300 toabout 1100 ng/dL in a male subject, and about 30 to about 110 ng/dL in afemale subject, over a time period of about 8 hours to about 24 hours.

The terms “effective amount” or “therapeutically effective amount” asused herein refer to a nontoxic but sufficient amount of the therapeuticagent to provide the desired therapeutic effect within a subject. Theexact amount that is “effective” will vary from subject to subject,depending on the age, weight and general condition of the subject, theseverity of the condition being treated, the judgment of the clinician,and the like. However, an appropriate “effective amount” in anyindividual case can be determined by one of ordinary skill in the artusing only routine experimentation, based on the disclosure herein.

Preferably, the formulations are prepared so as to contain a sufficientamount, i.e., dose of TU within a dosage unit, e.g., a capsule. It ispreferred that the amount of testosterone will be present in theformulation so as to provide each dosage form with a unit dosage of fromabout 1 to about 1000 mg, and preferably about 40 to about 400 mg oftestosterone undecanoate for oral administration, and preferably from200 to 1000 mg for parenteral. Typically the testosterone and/ortestosterone ester is from about 0.1% to about 80% of the formulation byweight. Preferably, the testosterone and/or testosterone ester is fromabout 0.1% to about 50% of the formulation by weight. More preferably,the testosterone and/or testosterone ester is from about 0.1% to about40% of the formulation by weight. In various other embodiments, thetestosterone and/or testosterone ester may be in a range having a lowervalue of any of 0.01, 0.05, 0.1, 0.15, 0.2, 0.5 and 1%, and having anupper value of any of 70.5, 71.0, 71.25, 71.5, 71.75, 72.0, 73.0, 74.0,75.0, 77.5, 79.0, 79.5, 79.75, 79.9, 79.95 and 80.0%.

In one embodiment, it is particularly preferred that the entire amountof TU is solubilized in the composition. However, it is sometimesnecessary to add additional TU in non-solubilized form when the TUsolubility capacity of a given composition is exceeded. Therefore, it isalso an important feature of the present invention that the TU presentin the composition is significantly solubilized. Typically, at leastabout 20% of the TU is solubilized in the composition and preferably atleast about 50% of the TU is solubilized in the composition of thedosage form. The dosage form contains TU solubilized in the compositionin an amount of at least about 1 mg, preferably in an amount of at leastabout 40 mg, and more preferably in an amount of at least about 100 mg.

Although the formulation may be administered to a subject in anysuitable dosage form, the dosage form is preferably a capsule or otheroral dose form (e.g., a tablet, lozenge, etc.) containing theformulation having a therapeutically effective amount of testosteroneand/or testosterone undecanoate contained therein. In an additionalembodiment, the dosage form is preferably a formulation suitable forparenteral administration, e.g. an intra-muscular injection.

The amount of solubilizer that can be included in a formulation of thepresent invention is not particularly limited. When the formulation isadministered to a subject, however, the amount of any given solubilizeris limited to a bio-acceptable amount. Bio-acceptable amounts ofsolubilizers and other components are readily determined by one of skillin the art by using routine experimentation or searching the literature.In some circumstances, it may be advantageous to include amounts ofsolubilizers far in excess of bio-acceptable amounts, for example, tomaximize the concentration of the TU, with excess solubilizer removedprior to providing the composition to a patient. Excess solubilizer maybe removed using conventional techniques such as distillation, spraydrying, lyophilization or evaporation. Generally, the amount ofsolubilizer in the composition will be from about 10% to about 90%,preferably between about 12.5% to about 85% by weight. In various otherembodiments, the solubilizer may be in a range having a lower value ofany of 0.01, 9.05, 9.1, 9.15, 9.2, 9.5 and 10%, and having an uppervalue of any of 80.5, 81.0, 81.25, 81.5, 81.75, 82.0, 83.0, 84.0, 85.0,87.5, 89.0, 89.5, 89.75, 89.9, 89.95 and 90.0%.

In one embodiment, the formulation also contains 1% to 99% by weight ofa sterol and/or sterol ester. In a preferred embodiment the formulationcontains about 1% to about 90% of phytosterol and/or phytosterol esters,solubilized and/or suspended. Preferably, the formulation contains fromabout 1% to about 70% of phytosterols and/or phytosterol esters; morepreferably, the formulation contains from about 1% to about 45% ofphytosterols and/or phytosterol esters. In a more preferred embodiment,the formulation contains about 2% to about 20% solubilized phytosterolsor phytosterol esters. In a further embodiment, additional phytosterolsor phytosterol esters may be co-dosed with a formulation of theinvention. In various other embodiments, the total phytosterol and/orphytosterol esters, solubilized and/or suspended may be in a rangehaving a lower value of any of 0.01, 0.05, 0.1, 0.15, 0.2, 0.5 and 1%,and having an upper value of any of 80.5, 81.0, 81.25, 81.5, 81.75,82.0, 83.0, 84.0, 85.0, 87.5, 89.0, 89.5, 89.75, 89.9, 89.95 and 90.0%.

In a further embodiment of the invention, phytosterols or phytosterolesters may be added with the therapeutic agent in solubilized form, insuspended form, as an additive, as a co-dose accompanying dosing of aformulation of the invention, or any combination thereof.

The amount of additional components in a formulation of the inventioncan be determined by one of ordinary skill in the art, according to thedesired property or properties to be imparted to the composition. Forexample, the amount of a suspending agent may be determined by addinggradual amounts of the agent until the desired homogeneity ofun-dissolved drug particles in the composition is achieved. For acolorant, the amount of the colorant may determined by adding smallamounts of the colorant until the desired color of the composition isachieved. For a surfactant, the amount of a surfactant may determined byadding gradual amounts of the surfactant until the desired wettingeffect or dispersibility of the composition is achieved. The amount ofsurfactant, when present, in the composition will generally be up toabout 80 wt. %, preferably between about 1 wt. % to about 50 wt. %, morepreferably between 1 wt. % to about 35 wt. %.

In a particular embodiment, the invention provides a formulationcontaining a therapeutically effective amount of a hydrophobic drug, aphytosterol and/or phytosterol ester, and a LCPUFA, LCPUFA oils, LCPUFAesters or mixtures thereof. The hydrophobic drug is present in an amountof from about 0.1 to 70% w/w of the composition. Furthermore, thehydrophobic drug is at least about 20% solubilized in the composition.The LCPUFA substance in the composition is present in an amount of fromabout 1 to 99% w/w of said composition. The phytosterols and/orphytosterol esters are suspended in the formulation in an amount of from1% to 40%.

In a further embodiment, a formulation of the invention may be providedas a pharmaceutical composition. As such, the formulation is provided ina dosage form, for administration to a subject in need of suchformulation.

Administration of a formulation of the invention may be as a singlecomposition, or as multiple compositions. The formulations andcompositions thereof maybe administered at the same time or may beadministered at different times. Administration may be performed by anymethod which results in the desired serum concentration of therapeuticagent.

In a preferred embodiment, the pharmaceutical composition is present ina single dosage form. The dosage form(s) are not limited with respect tosize, shape or general configuration, and may comprise, for example, acapsule, a tablet or a caplet, or a plurality of granules, beads,powders or pellets that may or may not be encapsulated. A preferreddosage form is a capsule containing a composition as described herein(FIG. 1). The capsule material may be either hard or soft and isgenerally made of a suitable compound such as gelatin, starch or acellulosic material. As is known in the art, use of soft gelatincapsules places a number of limitations on the compositions that can beencapsulated. See, for example, Ebert (1978), “Soft Elastic GelatinCapsules: A Unique Dosage Form,” Pharmaceutical Technology 1(5).Two-piece hard gelatin capsules are preferably sealed, such as withgelatin bands or the like. See, for example, Remington: The Science andPractice of Pharmacy, Twenty first Edition. (2006) cited supra, whichdescribes materials and methods for preparing encapsulatedpharmaceuticals. In this embodiment, the encapsulated composition may beliquid or semi-solid (e.g., a gel).

The formulation may optionally include a carrier, in addition to thetherapeutic agent, sterol and solubilizer. In one embodiment, thecarrier contains the solubilizer. In one embodiment, the carrierincludes one or more solubilizers and, optionally further includes oneor more pharmaceutically acceptable additives in addition to thesolubilizer.

“Carrier” or “vehicle” as used herein refers to carrier materialssuitable for drug administration. Carriers and vehicles useful hereininclude any such materials known in the art, e.g., any liquid, gel,solvent, liquid diluent, solubilizer, surfactant, or the like, which isnontoxic and which does not interact with other components of thecomposition in a deleterious manner.

In one embodiment of the invention, the formulation is provided in alipid suspension as a pharmaceutical composition.

The lipids may be of animal, vegetable or mineral origin, which aresubstantially water-insoluble, inert, non-toxic hydrocarbon fats andoils and derivatives thereof, and may comprise any of the commonlycommercially available fats or oils approved by the Food & DrugAdministration. The lipid may be a liquid or a solid at roomtemperature. Preferably, the lipid has a melting point in the range ofabout 90 to 160° F. (32 to 71° C.). The lipid may comprise a vegetableoil base commonly known as hard butter. Hard butters are hydrogenated,press fractionated, or other processed oils that are processed orrecombined to have a solid fat index (percent solid fat vs. temperature)similar to that of cocoa butter. However, other lipids may be used thatare relatively hard or solid at room temperature, but melt rapidly inthe mouth at a temperature of about 92° to 98° F. (29 to 32° C.). Thelipid is employed in the amounts within the range of from about 20 toabout 50%. Examples of suitable lipids include tallow, hydrogenatedtallow, hydrogenated vegetable oil, almond oil, coconut oil, corn oil,cottonseed oil, fish oil, light liquid petrolatum, heavy liquidpetrolatum, olein, olive oil, palm oil, peanut oil, persic oil, sesameoil, soybean oil, castor oil or safflower oil.

Additionally, stearines can be used as a lipid in the present invention.The addition of stearines to the product provides the favorable propertyof mold-release.

Furthermore a pharmaceutical composition of the invention may comprise afiller. Fillers of the present invention are pharmacologically inert andoptionally nutritionally beneficial to humans and animals. Such fillersinclude cellulose such as microcrystalline cellulose, grain starchessuch as cornstarch, tapioca, dextrin, sugars and sugar alcohols such assucrose, sorbitol, xylitol, mannitol and the like. Preferred fillersinclude non-fat milk powder, whey, grain brans such as oat bran, andfruit and vegetable pulps. Preferred fillers are finely divided and havea preferred average particle size in the range of about 0.10 to about500 microns. The fillers are present in the drug delivery device in aconcentration of about 50 to 80%. Optionally, the pharmaceuticalparticles can also serve as filler in the delivery system. Optionally,the filler may include sterols, particularly phytosterols. (See Example9 for use of microcrystalline cellulose for making a solid dosage formof the present invention).

In one embodiment of the invention the therapeutic agent ismicroencapsulated. Such microencapsulation includes sustained releaseencapsulation. Any known method of encapsulation is suitable in thepresent invention. Such methods include, but are not limited to aircoating, chemical erosion, coacervation, fluid bed coating,macroencapsulation, microencapsulation, osmosis, pan spray coating,physical erosion, polymer protein conjugate systems, and polymericmicrospheres. A preferred method involves slowly blending the drug witha filming agent solution to form granulated particles. The granulatedparticles are allowed to dry on a tray and are sieved to the desiredsize, typically in the range of from about 200 to about 500 microns. Thecoating materials include, but are not limited to, acrylic polymers andco-polymers, alginates, calcium stearate, cellulose, includingmethylcellulose, ethylcellulose, and hydroxypropyl cellulose, gelatins,glyceryl behenate, glycholic acid and its various forms, ion exchangeresins, lactic acid and its various forms, lipids, methacrylic monomers,methacrylic polymers and co-polymers, polyethylene glycol polymers,shellac (pharmaceutical glaze), stearic acid, glycerol esters of fattyacids and waxes. It is contemplated in the present invention that themicroencapsulated testosterone and/or testosterone ester may be usedalone, or in the lipid suspension. Further, the microencapsulatedtestosterone and/or testosterone ester may be used in any other system,such as tablets, boluses, enclosed in a gelatin capsule, or in a liquidor syrup system.

In another embodiment of the present invention, the therapeutic agent isnot microencapsulated, but suspended in the lipid as dry particles.Where the therapeutic agent is a testosterone and/or testosterone ester,typically the testosterone and/or testosterone ester is present in thedelivery device in a concentration of 50% or less. However, thetestosterone can comprise all of the dried particles, to provide thenecessary dose.

Optionally, the dry particles include flavorings that make the devicetaste and smell appealing to humans or animals. The flavorings can benatural or synthetic, and can include fruit flavorings, citrus, meat,chocolate, vanilla, fish, butter, milk, cream, egg or cheese. Theflavorings are typically present in the device in the range of about0.05 to about 1.0%.

The delivery device may also include other pharmaceutically acceptableagents, such as sweetening agents, including hydrogenated starchhydrolysates, synthetic sweeteners such as sorbitol, xylitol, saccharinsalts, L-aspartyl-L-phenylalanine methyl ester, as well as coloringagents, other binding agents, lubricants, such as calcium stearate,stearic acid, magnesium stearate, antioxidants such as butylated hydroxytoluene, antiflatulants such as simethicone and the like.

Optionally, rupturing agents are used to rapidly deliver thetestosterone and/or testosterone ester into the recipient's system. Atypical rupturing agent is a starch that swells in the presence ofwater. Various modified starches, such as carboxymethyl starch,currently marketed under the trade name Explotab or Primojel are used asrupturing agents. A preferred rupturing agent is sodium starchglycolate. When ingested, the capsule or pellet swells in the presenceof gastric juices and ruptures.

In one embodiment of the present invention, the rupturing agent ispresent with the therapeutic agent inside the microcapsule. As waterpenetrates the microcapsule, it swells the starch and ruptures thecapsule, rapidly delivering the testosterone undecanoate to the system.Additional rupturing agents are disclosed in U.S. Pat. No. 5,567,439,which is hereby incorporated by reference.

In another embodiment, the rupturing agent is present in the lipidsuspension, which ruptures the pellet, but leaves the microcapsulesintact. This allows delayed delivery of the drug farther along in thedigestive system, or in the intestines. The present invention isparticularly effective in this embodiment, in that the ingested pelletmay be chewable, where the pellet cleaves in the lipid suspension whenchewed, but leaves the microcapsules intact. Tablets or gel capsules,when chewed, typically result in damage to or rupturing of themicrocapsules defeating the effectiveness of the microcapsules.

In yet another embodiment, multiple drugs have multiple encapsulations,each containing a rupturing agent. The filming agents used forencapsulation are selected to disintegrate at selected pH conditions,which rupture and release each drug at desired locations in thedigestive system.

The formulations of the present invention are prepared by conventionalmethods well known to those skilled in the art. The formulation can beprepared by mixing the active agent, the solubilizer, and optionaladditive according to methods well known in the art. Excess solvent orsolubilizer, added to facilitate solubilization of the active agentand/or mixing of the formulation components, can be removed beforeadministration of the pharmaceutical dosage form. The compositions canbe further processed according to conventional processes known to thoseskilled in the art, such as lyophilization, encapsulation, compression,melting, extrusion, balling, drying, chilling, molding, spraying, spraycongealing, coating, comminution, mixing, homogenization, sonication,cryopelletization, spheronization and granulation to produce the desireddosage form.

For dosage forms substantially free of water, i.e., when the compositionis provided in a pre-concentrated form for administration or for laterdispersion in an aqueous system, the composition is prepared by simplemixing of the components to form a pre-concentrate. The compositionscomprising solubilized TU can be further formulated into desirabledosage forms utilizing skills well known in the art. For example,compositions in liquid or semi-solid form can be filled into softgelatin capsules using appropriate filling machines. Alternatively, thecomposition can also be sprayed, granulated or coated onto a substrateto become a powder, granule or bead that can be further encapsulated ortableted or molded if the compositions solidify at room temperature withor without the addition of appropriate solidifying or binding agents.This approach allows for the creation of a “fused mixture,” a “solidsolution” or a “eutectic mixture.”

For example, testosterone undecanoate and phytosterols form a eutecticmixture when the ratio of TU:phytosterols is 80:20. The melting point ofthe eutectic is 54° C. while the melting points of TU and phytosterolsare 60° C. and 137° C., respectively. The dissolution profile of theeutectic is shown in FIG. 2.

FIG. 2 provides the dissolution profiles of each of Formulations 9, 51,53, and 55, as set forth in Tables 2 and 20 herein and Capsules 2 and 4from Example 1 of US2010/0173882. The data were obtained in adissolution medium incorporating 2% TritonX-100 as a surfactant in theUSP 2 apparatus in accordance with the present invention. Thedissolution profiles of formulations in the present invention areclearly different from those in US2010/0173882. Formulations 51, 53 and55 were used in the human clinical study described in Example 8.

Not previously identified is an effect observed in FIG. 4 depicting thedissolution profile of a formulation saturated with phytosterols(Formulation 59) and one in which excess phytosterols have been added toform a waxy solid (Formulation 61) that the concentration ofphytosterols may be used to modulate the dissolution profile offormulations containing phytosterols. The dissolution profiles of FIGS.2 and 4 illustrate that at higher concentrations phytosterols functionto retard the dissolution of the therapeutic agent (FIG. 4).

FIG. 4 provides dissolution curves of TU from formulations 59, 60, and61 (Table 22). Dissolution was measured in 900 mL of 25 mM phosphatebuffer at pH 7.0 containing 0.1% SLS, obtained at 200 rpm using USP 2apparatus. Formulation 59 illustrates the dissolution of a formulationwith the properties of remaining a liquid a room temperature, whileFormulation 60 is a suitable formulation which is solid at roomtemperature. Phytosterols in excess of the amount soluble at 70° C. maybe added to the composition to modulate the release rate, as illustratedby the dissolution profile of Formulation 61 in FIG. 4. Formulation 61further has the desirable property of being a sufficiently hard materialthat it may be reduced to a powder, which is fillable into a capsule byordinary means.

As previously indicated, the compositions may include additional amountsof T or TU over the amount that is solubilized in the composition. Insuch a case, TU can be partially suspended in the composition. Suchpartially solubilized and partially suspended TU compositions can beprepared by adding solids of T or TU of desired form and particle size.For example, micronized crystalline T or TU having an average particlesize of less than 30 microns, nanosized crystalline T or TU having anaverage particle size of less than 1 micron or amorphous T or TU may beadded to the composition. Such micronized or nanosized T and TUparticles can be obtained by precipitation or size reduction techniqueswell-known in the art. In addition, partially suspended T and/or TUcompositions may be obtained from a supersaturated T or TU solution orby co-precipitation with an additive from a T and/or TU solution.

It is particularly preferred that an orally administered drug deliverysystem be prepared by first embedding the therapeutic agent(s) intophytosterols and/or phytosterol esters and an organic polymer,separately or together, in a solid state as obtained by suspension oruse of a spray-drying process.

It is especially preferred to mix the testosterone products with otherauxiliary agents, binders, fillers, lubricants, surfactants ordisintegration accelerators and to compress or mold the mixture intotablets or fill into a capsule.

When testosterone and testosterone esters are employed along withphytosterols and/or phytosterol esters, the use of the embeddingtechnique of spray-drying in organic polymers (polyvinylpyrrolidone,hydroxypropylmethylcellulose and its derivatives, solid polyethyleneglycols), the solubility of the testosterone and testosterone esters inthe intestinal fluids is enhanced.

In one embodiment, a formulation of the invention is made by dissolvingtestosterone and/or the particular testosterone ester, phytosterolsand/or phytosterol esters together with the polymer (for examplepolyvinylpyrrolidone or hydroxypropyl-methylcellulose and itsderivatives) in ethanol and processing the mixtures further in aspray-drying unit to form an amorphous, embedded, spray-driedformulation. It is possible in this case 1) to embed said activeingredients separately from each other or 2) to embed them together in asingle processing step, to obtain an amorphous mixture.

In another embodiment, a formulation of the invention is made bysuspending crystalline or amorphous testosterone and/or the particulartestosterone ester, phytosterols and/or phytosterol esters in a lipidbased formulation containing one or more surfactants resulting in SEDDSor SMEDDS.

The fine-particle embedded spray-dried material or the SEDDS or theSMEDDS is then subjected to dry mixing with other auxiliary agents formaking tablets or capsules. The mixture is then compressed into tabletsor filled into capsules.

In order to obtain a formulation with the desired release patterns, itis advantageous to individually consider characteristics of theindividual components of the formulation, such as dosage of the activeingredient, ratio of testosterone to testosterone esters, selection ofthe ester or of the chain length at C-17 position of the androgenmoiety, level of phytosterols and/or phytosterol esters, length of fattyacid chain and unsaturation level of lipids, level of surfactants, andlevel of sustained release polymer.

An exemplary optimized formulation is a short-acting testosterone withtestosterone undecanoate (eleven-carbon chain) which has a longerhalf-life.

By skillful combination of testosterone with testosterone esters, in animmediate release and sustained release formulation, it is possible toattain blood level patterns which are capable of recreating orsimulating the body's own rhythmicity of endogenous testosterone levels.

The present inventor has shown that by the administration oftestosterone and/or testosterone undecanoate and phytosterol and/orphytosterol esters, it is possible to increase lymphatic absorption oftestosterone undecanoate and modulate levels of T and DHT (FIG. 10). Inselecting the testosterone ester, the choice can be made specificallyfrom three groups: 1) esters of shorter chain length (for example,testosterone acetate or propionate), 2) esters of medium chain length(for example testosterone enanthate, cypionate orcyclohexanecarboxylate) and 3) esters of higher chain length (forexample testosterone undecanoate, bucyclate or palmitate).

In another embodiment, the process for preparing the compositionincluding the formulation in a delivery system containing a lipidcomprises melting the lipid, phytosterols and/or phytosterol esters andmixing with the surfactant. The dry particles of the active substanceare mixed with the melted lipid/phytosterol mixture to form a suspensionexhibiting pseudoplastic and/or thixotropic flow properties, and pouredor molded to provide solid dosage forms (FIG. 1).

The dry particles, which include the testosterone and/or testosteroneester, filler and optional flavorings and additives, are pre-blended andtypically have a particle size in the range of from about 50 microns toabout 250 microns. The pre-blended particles are gradually added to theheated lipid base containing phytosterols and/or phytosterol estersuntil a high solids suspension is obtained, typically in the range ofabout 50% to about 80% particles and from about 50% to about 20% lipid.

Slow addition of the dry particles is critical in the production of thedevice, to ensure that the particles are suspended in their micronizedstate and not as agglomerated clumps. Moreover, rapid addition can causethe mixing process to fail in that the melted suspension will not havethe desired flow properties, but instead will be a granular oily mass (asign of product failure). The mixing step is accomplished in a heatedmixing device that insures thorough mixing of all materials with minimalshear, such as a planetary mixer or a scrape surface mixer. After thesuspension is formed, the product is poured into molds and allowed tocool. De-molding and packaging are then performed. Alternatively, thesuspension can be super-cooled and sheeted in a semi-soft format. Thesheet is processed through forming rolls containing a design orconfiguration that embosses and forms the final shape.

The formulations and pharmaceutical compositions of the invention areuseful in methods of treatment of subjects in need of such treatment.For example, the testosterone-containing formulations and pharmaceuticalcompositions described herein can be administered to patients who wouldbenefit from testosterone replacement therapy. Patients suffering fromany condition, disease or disorder which can be effectively treated withtestosterone can benefit from the administration of a therapeuticallyeffective amount of the testosterone-containing compositions describedherein. In particular, however, the testosterone-containing compositionsare effective in treating individuals suffering from androgen deficiency(e.g., postmenopausal women, menopausal women, sexually dysfunctionalwomen, andropausal men, hypogonadal men, erectile dysfunctional men andthe like).

In one embodiment the invention provides a method of treating acondition comprising administering: a) at least one lipophilic, poorlywater soluble therapeutic agent; b) a phytosterol or phytosterol ester;c) a non-sterol solubilizing agent effective for solubilization of theat least one therapeutic agent; and d) an enhancing agent effective toenhance the biological absorption and/or metabolic stability of the atleast one therapeutic agent. In a particular embodiment, the therapeuticagent is an androgen, and in a more particular embodiment, the androgenis selected from testosterone and testosterone esters, such astestosterone undecanoate. In a preferred embodiment the sterol or esterthereof is a phytosterol.

In a particular embodiment the invention provides a method of treating asubject in need of treatment for erectile dysfunction wherein the methodcomprises administration of two therapeutic agents, a first therapeuticagent comprising an androgen and a second therapeutic agent comprising aPDE V inhibitor, including, but not limited to, tadalafil (Clalis®),sildenafil (Viagra®), and vardenafil (Levitra®).

In order to characterize the absorption and bioavailability of theformulations of the present invention, animal models can be used. Asnoted above, Shackleford et al studied testosterone exposure in dogsdosed with testosterone undecanoate (Shackleford et al., J. Pharmacol.And Exptl. Therap., 2003, vol. 306, no. 3, pp. 925-933.) anddemonstrated that TU is almost exclusively absorbed through intestinallymphatics by-passing the liver. Canine models are generally accepted inthe art as predictive of human efficacy with respect to oraladministration of testosterone and its esters.

Formulations of the present invention were tested in canine models, asdescribed in Examples 4 and 5 below, which demonstrates improved TUabsorption when co-dosed with phytosterols, as compared to TU dosed froma reference formulation composition similar to that of Andriol®Testocaps® (Table 23 and 24).

The inventor has found that phytosterols have unexpectedly enhanced thesolubility of testosterone and/or testosterone esters in a range oflipid-based formulations from simple one lipid solubilizer component tocomplex 3-5 lipid solubilizer and surfactant SEDDS and/or SMEDDSformulations from about 1% to about 40% (Tables 1-20). The formulationshave been divided into various classes I through VII depending on thecomplexity of the formulation. These tables also provide thecompositions of representative formulations of the invention along withmethod of making them. The solubility of testosterone undecanoate inselected fatty acids, triglycerides, mono- and diglycerides,surfactants, emulsifiers, antioxidants and co-solvents were measured toselect excipients for preparing representative examples offormulation(s) for each class (Table 1). The clinical formulation wasalso prepared with different sterols: Phytosterols, Cholesterol,Beta-sitosterol, Sitostanol (Table 19). It was unexpectedly discoveredthat testosterone and testosterone undecanoate enhance each other'ssolubility when saturated with phytosterols (Tables 16-18).

Dosage regimens and daily dosages for testosterone can vary, as a numberof factors are involved, including the age and general condition of thepatient.

The present invention relates to a method of administering a combinationof testosterone and/or testosterone esters, phytosterols and/orphytosterol esters, mono and polyunsaturated oils and/or esters of monoand polyunsaturated oils and/or mono and polyunsaturated fatty acids inan oral preparation so that, by finely adjusted dosing of the activeingredients with improved sustained release properties, various desiredplasma levels of testosterone can be set or produced in individualpatients, for example to restore an endogenous body rhythm. Thetestosterone, when delivered in the present invention, may provideimproved sustained release properties with an improvement of 10-300%over that shown in the art using micronized/nanomilled testosteronealone or testosterone undecanoate in a commercial formulation (Andriol®Testocaps®). In the delivery system, the testosterone and testosteroneesters may be delivered as a solid (capsule or tablet), liquid lipidsolution, or liquid lipid suspension.

In another embodiment, the invention provides a method of administeringa combination of testosterone and testosterone esters (or solelytestosterone esters), phytosterols and/or phytosterol esters, mono andpolyunsaturated oils and/or esters of mono and polyunsaturated oilsand/or mono and polyunsaturated fatty acids in an oral preparation sothat, by finely adjusted dosing of the active ingredients with immediateand/or modified release properties and targeted delivery in variousregions of the GI tract, various desired plasma levels of testosteronecan be set or produced in individual patients along with maintaining orcontrolling normal physiological levels of dihydrotestosterone (DHT).

DHT levels in eugonadal men are typically about 1/10^(th) that oftestosterone (i.e. about 30-110 ng/dL). Modified release dosage formsinclude but are not limited to those where drug release is modulated bygastric retention, muco-adhesion, time, pH, enzymes, or pressure. Inthis context, improved modified release properties are adjustment ofrelease so that the amount of DHT relative to testosterone is minimized.Testosterone interacts with receptive androgen receptors either directlyor following its conversion to DHT via the action of 5-alpha-reductase.DHT is a more potent androgen than testosterone and elevated DHT levelsare thought by some scientists to increase the risk of benign prostatehyperplasia (BPH) and prostate cancer. Elevated levels of DHT are anoted problem with the oral or transdermal administration oftestosterone and/or testosterone esters.

In one embodiment the invention provides a method of maintaining orcontrolling physiological levels of DHT in a subject in need oftestosterone replacement such that the physiological levels of DHT arenormal or near normal and supra-physiological levels of DHT are avoidedby such control or maintenance. In a particular embodiment the methodfor maintaining or controlling physiological levels of DHT in a subjectin need of testosterone replacement comprises administration of 1)testosterone and/or testosterone undecanoate, 2) a sterol or esterthereof; 3) a non-sterol solubilizing agent effective for solubilizationof the T or TU; and 4) an agent for enhancing the biological absorptionand/or metabolic stability of the T or TU. In a preferred embodiment thesterol or ester thereof is a phytosterol. In a further preferredembodiment, the method results in total serum testosterone in thesubject in the range of from about 300 to about 1100 ng/dL and totalserum DHT in the subject in the range of from about 30 to 300 ng/dL,where the subject is a male subject. In an additionally preferredembodiment, the further embodiment the method results in total serumtestosterone in the subject in the range of from about 30 to about 110ng/dL, where the subject is a female subject.

The testosterone and/or testosterone esters, when delivered, may providetotal serum testosterone in the desired range for a period of eight (8)to twelve (12) or more hours. In one embodiment, the total serumtestosterone is maintained in the desired range for up to about 24hours.

Preferably, the sterol and/or sterol esters, essential fatty acids,essential fatty acid oils, and essential fatty acid esters andtherapeutic agent exert an additive or synergistic therapeutic effect orthe sterols mediate negative side effects of the therapeutic agent.

The formulations and pharmaceutical compositions of the invention arefurther useful in methods of treatment of additional hormonedeficiencies and associated effects.

Accordingly the invention provides a method of treating an androgendeficiency in a subject, where the method includes administering apharmaceutical composition of the invention.

In various embodiments the invention provides formulations and methodsincluding biological absorption of one or more therapeutic agents. Theroute of such absorption is determined by the therapeutic agent used,additional elements of the formulation and/or the method ofadministration. In various embodiments, the absorption compriseslymphatic absorption and/or portal absorption. In specific embodimentsthe absorption comprises lymphatic absorption of testosteroneundecanoate.

The invention, as variously described herein in respect of features,aspects and embodiments thereof, may in particular implementations beconstituted as comprising, consisting, or consisting essentially of,some or all of such features, aspects and embodiments, as well aselements and components thereof being aggregated to constitute variousfurther implementations of the invention. The invention is describedherein in various embodiments, and with reference to various featuresand aspects of the invention. The invention contemplates such features,aspects and embodiments in various permutations and combinations, asbeing within the scope of the invention. The invention may therefore bespecified as comprising, consisting or consisting essentially of, any ofsuch combinations and permutations of these specific features, aspectsand embodiments, or a selected one or ones thereof.

The compositions of the invention may be further specified in specificembodiments by provisos or limitations excluding specific substituents,groups, moieties or structures, in relation to various specificationsand exemplifications thereof set forth herein. Thus, the inventioncontemplates restrictively defined compositions, e.g., a compositionexcluding one or more specified ingredients.

The advantages and features of the invention are further illustratedwith reference to the following examples, which are not to be construedas in any way limiting the scope of the invention but rather asillustrative of various embodiments of the invention in specificapplications thereof.

EXAMPLE 1 Evaluation of TU Solubility with & without Sterols inFormulations of Varying Complexity

The solubility of TU in various solubilizers was determined usingconventional techniques such as incrementally adding TU until thesolubilizer could no longer solubilize additional material. Table 1below lists experimentally measured solubilities of testosteroneundecanoate (TU) in various excipients of interest. Formulations 1-50below starting with simple one component to complex 4-6 components(Classes I through VII) were then prepared representing differentcategories of solubilizers. The solubility of TU and/or T was enhancedby sterols (phytosterols, cholesterol, sitostanol, and beta-sitosterol)by 1-40%. The extent of enhancement is governed by the properties ofsolubilizers, emulsifiers, and surfactants selected to form theformulation.

The formulations listed in Tables 1 to 20 were prepared by combining theexcipients, except phytosterols, in the proportions given. Theformulation was then completed by saturating with phytosterols and theaddition of active agent to the desired level.

TABLE 1 Testosterone undecanoate (TU) solubility in various solubilizersTU Solubility Vehicle (mg/g) at 37 C. Oleic acid 405 Linoleic acid 391Linolenic acid 162 Ricinoleic acid 244 Caprylic acid 595 Incromega E7010(omega-3) 247 Incromega TG7010 SR (omega-3 high purity) 225 Omega-3ethyl esters w/antioxidant (AMRI) 261 Omega-3 ethyl esters w/oantioxidant (AMRI) 360 Crodamol IPM (isopropyl myristate) 295 CrodamolIPP (isopropyl palmitate) 215 Crodamol EO (ethyl oleate) 221 Ethyllinoleate 230 Sunflower oil 105 Safflower oil 124 Sesame oil 138 Castoroil 218 Canola oil 167 Corn oil 243 Maisine 35-1  93 Linseed oil 179Olive oil 161 Glyceryl trioleate (Capmul GTO) 154 Rapeseed oil 123Soybean oil 113 Acconon CO-7  59 Miglyol 812 >100* Capmul MCM >100*Capmul PG-8 >100* Propylene glycol monolaurate >200* Glyceryl mono anddicapylate/caprate (Imwitor 742) 356 Glyceryl monooleate or GMO (Peceol(Gattefosse)) 323 Glyceryl ricinoleate (Softigen 701) 261 Propyleneglycol monocaprylate (Capryol 90, Gattefosse) 486 Labrasol  43* LabrafilM 1944 CS 242 Labrafil M 2125 CS 257 Polyglyceryl-3-dioleate (Plurololeique CC497) 193 Polyglyceryl-3-diisostearate (Plurol diisosterique)173 Polyglyceryl-6-dioleate (Caprol MPGO, Abitec) 184 Span 80 289Polysorbate 85 125 Cremophor RH40  88* Polysorbate 80 (Tween 80)  39*N-methyl pyrolidone >500  Transcutol HP 180 dl-alpha-tocopherol 527Phosal 50 PG (~50% Lecithin in PG, sunflower mono- 138 diglycerides andascorbyl palmitate) *Solubility determined at 25° C.

TABLE 2 Class I: TU + Phytosterols Formulation # TU % Phytosterols % 1 595 2 10 90 3 20 80 4 30 70 5 40 60 6 50 50 7 60 40 8 70 30 9 80 20 10 9010 11 95 5

TABLE 3 Class II: TU + 1 Lipid Solubilizer + Phytosterols % Composition(w/w) Formulation # 12 13 Ω-3 Ethyl esters w 100 antioxidant Oleic acid100 TU solubility mg/gm 246 385 TU solubility mg/gm 290 418 saturatedwith phytosterols Percent change in 17.9% 8.6 solubility

TABLE 4 Mono/diglyceride or Polyoxylglyceride Based % Composition (w/w)Formulation # 14 15 GMO (Peceol) 100 — Labrafil M 1944 CS — 100 TUsolubility mg/gm 257 242 TU solubility mg/gm saturated 317 275 withphytosterols Percent change in solubility 23.3 13.6

TABLE 5 Class III: TU + 1 Lipid Solubilizer + Surfactant + PhytosterolsTriglyceride or Fatty Acid Based % Composition (w/w) Formulation # 16 1718 Corn oil 65 Oleic acid 65 Caprylic acid 65 Cremophor RH40 11.67 11.6711.67 Tween 80 23.33 23.33 23.33 TU solubility mg/gm 218 254 407 TUsolubility mg/gm w/ 237 354 469 phytosterols Percent change in 8.7%39.4% 15.2% solubility

TABLE 6 Mono/diglyceride Based % Composition (w/w) Formulation # 19 20GMO (Peceol) 65 Capryol 90 65 Cremophor RH40 11.67 11.67 Tween 80 23.3323.33 TU solubility mg/gm 221 272 TU w/phytosterols 233 352 Percentchange in solubility 5.4% 29.4%

TABLE 7 Polyoxylglyceride Based % Composition (w/w) Formulation # 21Labrafil M 2125 CS 65 Cremophor RH40 11.67 Tween 80 23.33 TU solubilitymg/gm 191 TU solubility mg/gm w/ 252 phytosterols Percent change insolubility 31.9%

TABLE 8 Class IV: TU + 2 Lipid Solubilizers + Surfactant + PhytosterolsFatty acid based Table 1 % Composition (w/w) Formulation # 22 23 24 25Oleic acid 39.85 47.86 Caprylic acid 29.07 38.20 GMO (Peceol) 25.1535.93 Capryol 90 17.14 26.80 Cremophor RH40 11.67 11.67 11.67 11.67Tween 80 23.33 23.33 23.33 23.33 TU solubility 245 264 252 328 mg/gm TUsolubility 258 331 309 390 mg/gm s when saturated with phytosterolsPercent change in 5.3 25.4 22.6 18.9 solubility

TABLE 9 Class IV: TU + 2 Lipid Solubilizers + Surfactant + PhytosterolsTriglyceride based % Composition (w/w) Formulation # 26 27 Castor oil 40Corn oil 40 Labrafil M 2125 CS 25 25 Cremophor RH40 11.67 11.67 Tween 8023.33 23.33 TU solubility mg/gm 143 144 TU solubility mg/gm w/ 195 162phytosterols Percent change in solubility 36.4 12.5

TABLE 10 Class V: TU + 3 Lipid Solubilizers + Surfactant (1 CremophorRH40: 2 Tween 80) + Lecithin + HPMC + Phytosterols % Composition (w/w)Formulation # 28 29 Oleic acid 30.05 30.05 GMO (Peceol) 18.97 18.97Labrafil M 2125 CS 14.71 14.71 Cremophor RH40 11.44 Tween 80 22.87 34.31Lecithin 0.98 0.98 HPMC 0.98 0.98 TU solubility mg/gm 263 240 TUsolubility mg/gm 277 293 saturated with phytosterols Percent change in5.3 22.1 solubility

TABLE 11 % Composition (w/w) Formulation # 30 31 32 Oleic acid 30.0530.05 30.05 Capryol 90 18.97 18.97 18.97 Labrafil M 2125 CS 14.71 14.7114.71 Cremophor RH40 11.44 34.31 Tween 80 22.87 34.31 Lecithin 0.98 0.980.98 HPMC 0.98 0.98 0.98 TU solubility mg/gm 238 231 240 TU solubilitymg/gm 277 277 282 saturated with phytosterols Percent change in 16.419.9 17.5 solubility

TABLE 12 % Composition (w/w) Formulation # 33 34 Caprylic acid 30.0530.05 GMO (Peceol) 18.97 18.97 Labrafil M 2125 CS 14.71 14.71 CremophorRH40 11.44 34.31 Tween 80 22.87 Lecithin 0.98 0.98 HPMC 0.98 0.98 TUsolubility mg/gm 328 320 TU solubility mg/gm 354 351 saturated withphytosterols Percent change in 7.9 9.7 solubility

TABLE 13 % Composition (w/w) Formulation # 35 36 Caprylic acid 30.0530.05 Capryol 90 18.97 18.97 Labrafil M 2125 CS 14.71 14.71 CremophorRH40 11.44 Tween 80 22.87 34.31 Lecithin 0.98 0.98 HPMC 0.98 0.98 TUsolubility mg/gm 301 317 TU solubility mg/gm 319 340 saturated withphytosterols Percent change in 6.0 7.3 solubility

TABLE 14 % Composition (w/w) Formulation # 37 38 39 Oleic acid 45.7545.75 45.75 GMO (Peceol) 28.88 28.88 28.88 Labrafil M 2125 CS 22.3922.39 22.39 Cremophor RH40 1 0.33 Tween 80 1 0.67 Lecithin 0.99 0.990.99 HPMC 0.99 0.99 0.99 TU solubility mg/gm 384 368 366 TU solubilitymg/gm 393 410 410 saturated with phytosterols Percent change in 2.3 11.412.0 solubility

TABLE 15 % Composition (w/w) Formulation # 40 41 Castor oil 30.00Miglyol 30.00 Lauryl glycol 20.00 20.00 Labrafil M 1944 CS 15.00 15.00Cremophor RH40 35.00 35.00 TU solubility mg/gm 115 123 TU solubilitymg/gm 143 127 saturated with phytosterols Percent change in solubility24% 3.3%

Class VI: Formulations of T and TU with and without PhytosterolSaturation

Formulations 42-45 were prepared first without phytosterols and thensaturated with phytosterols. First, the added T was used to estimate theamount of solid required to produce saturation. These samples were usedto determine the solubility of T in the vehicles. As soon as the Tloading was known (e.g., 1 day), the same vehicles were prepared withboth T and TU above saturation.

TABLE 16 Composition (% w/w) Composition (% w/w) Formulation # 42 43Castor oil 29.30 — Lauroglycol 18.73 — Labrafil M 1944 CS 13.95 13.83Cremophor RH40 34.08 11.64 OA — 29.80 GMO (Peceol) — 17.99 Tween 80 —22.80 Lecithin 0.95 0.95 HPMC 0.95 0.95 Vit E 1.99 1.99 BHA 0.05 0.05 Talone solubility mg/gm 40 38 T alone solubility mg/gm 43 41 saturatedwith phytosterols Percent change in 7.5 7.9 solubility T solubilitymg/gm in 46 48 presence of saturated TU T solubility mg/gm in 47 51presence of saturated TU saturated with phytosterols Percent change in2.2 6.3 solubility TU solubility mg/gm in 183 204 presence of saturatedT TU solubility mg/gm in 205 218 presence of saturated T and saturatedwith phytosterols Percent change in 12.0 6.9 solubility

TABLE 17 Formulation # 44 Ingredient Composition (% w/w) Oleic acid 100T solubility mg/gm 35 T solubility mg/gm saturated with phytosterols 54T solubility mg/gm in presence of saturated TU 52 T solubility mg/gm inpresence of saturated TU 58 saturated with phytosterols Percent changein solubility 11.5% TU solubility mg/gm in presence of saturated T 425TU solubility mg/gm in presence of saturated T 431 and saturated withphytosterols Percent change in solubility 1.4%

TABLE 18 Formulation # 45 Ingredients Composition (% w/w) Oleic acid45.75 GMO (Peceol) 28.88 Labrafil M 2125 CS 22.39 Tween 80 1 Lecithin0.99 HPMC 0.99 T solubility mg/gm 51 T solubility mg/gm saturated withphytosterols 54 T solubility mg/gm in presence of saturated TU 51 Tsolubility mg/gm in presence of saturated TU 55 saturated withphytosterols Percent change in solubility 7.8 TU solubility mg/gm inpresence of saturated T 358 TU solubility mg/gm in presence of saturatedT 375 and saturated with phytosterols Percent change in solubility 4.7

TABLE 19 Class VII: Solubility of TU in Oleic Acid Based Formulationwith Cholesterol, Stigmastanol (β-sitostanol) and β-sitosterolComposition (% w/w) Formulation # 46 47 48 49 50 Ingredients OA OAOA-Chol OA-Stig OA-β- sitosterol OA 29.80 29.80 29.80 29.80 29.80 GMO(Peceol) 17.99 17.99 17.99 17.99 17.99 Labrafil M 13.83 13.83 13.8313.83 13.83 1944 CS Cremophor 11.64 11.64 11.64 11.64 11.64 RH40 Tween80 22.80 22.80 22.80 22.80 22.80 Sterol No Sat. w/ Sat. w/ Sat. w/ Sat.w/β- sterols phytos- Choles- Stigmastanol sitosterol terol terolLecithin 0.95 0.95 0.95 0.95 0.95 HPMC 0.95 0.95 0.95 0.95 0.95 Vit E1.99 1.99 1.99 1.99 1.99 BHA 0.95 0.05 0.05 0.05 0.05 TU solubility, 152155 162 160 179 mg/gm Percent change — 2.0 6.6 5.3 17.8 in solubilitycompared to the ‘no sterols’ column

TABLE 20 Clinical and animal study formulations RAW MATERIAL UnitFormulation % Formulation # 51 (clinical) 53 (clinical) 52 (animal)* 54(animal)* 55 (clinical) Testosterone Undecanoate 11.54 11.54 11.54Castor oil 25.40 Oleic acid 25.93 25.93 Lipoid E PC S (Egg Lecithin)0.85 0.85 0.85 Cremophor RH40 29.63 9.88 9.87 Polysorbate-80 19.74 19.73Labrafil M 1944 CS 12.70 11.69 5.17 Lauroglycol 90 16.93 Glycerylmono-oleate Type 40 15.37 8.85 Precirol ® 13.26 Phytosterols asCardioAid XF 2.12 2.11 2.12 Hypromellose 2910 (HPMC) 0.85 0.85 0.85dl-α-Tocopherol 2.00 1.77 Butylated Hydroxyanisole 0.05 0.05 0.05 (BHA)*Formulations used for animal studies did not contain dl-α-Tocopherol orBHA.

For those formulations where the level of phytosterols was achieved bysaturation, the level of phytosterols is from about 2% to about 20%. Thelevel of solubilizers ranges from about 10% to about 90%. The level ofsurfactants ranges from about 1% to about 35%.

This example shows that formulations containing TU and/or T may beprepared from the compositions of Table 1-20 to contain the active agentin any concentration up to the solubility shown. In addition, theformulation may be further modified by addition of testosterone and/ortestosterone ester beyond the solubility shown, while retaining usefuldissolution and other pharmaceutical properties. FIG. 4 of Example 3illustrates this modulation of properties.

EXAMPLE 2 Preparation of Compositions Comprising TestosteroneUndecanoate

Compositions comprising T, TU, and Phytosterol were prepared by weighingout the components in the described amount, placing the components intoan appropriate container, mixing the components in an appropriate mannerand, if necessary, heating to facilitate the solubilization of T, TU,and Phytosterols in the formulation. The formulations can be prepared byadding the components in any order. For example, T, TU, and phytosterolscan be added to an individual component or into mixtures of two or morecomponents. The composition can be prepared at room temperature orgently heated to 40-60° C. The composition can also be prepared bymelting TU or Phytosterol and/or phytosterol esters at a temperatureabove the melting point, i.e., 64-66° C., followed by mixing it withother components. Traditional mixing techniques can be used, including,for example, mechanical agitation, stirring and sonication of thecomponents. The clinical formulations 51, 53, and 55 were prepared usingsemi-automated equipment. A flow chart of a small-scale manufacturingprocess for preparation of pharmaceutical products suitable for clinicaluse is shown in FIG. 1. This process is suitable for the small scalemanufacture of HPMC capsules, and it is a simple matter to adapt theprocess to gelatin capsules by replacing the HPMC banding solution witha gelatin banding solution. Other means of sealing capsules are alsoavailable, such as the LEMS™ system used with LiCaps™. Formulationscontaining only TU and Phytosterols were prepared by melting the mixtureand cooling to room temperature. The solid was ground to a powder andfilled into gelatin or HPMC capsules.

Formulations which are liquid at room temperature can be converted intofree flowable powder or a waxy solid by addition of carriers or sprayingthe formulation on to an inert carrier. An example of preparing a solidpowder is given below in Table 21. The liquid formulation was preparedby heating TU, excess phytosterols, and all other excipients at 70° C.for one day and cooled to room temp. Microcrystalline cellulose wasadded to absorb the formulation and yield a solid that was ground to apowder and filled in a HPMC capsule. The dissolution profile of theformulation is shown in FIG. 3.

The dissolution profiles of selected formulations prepared in the abovemanner and chosen from Table 2-21 are shown in FIGS. 2 and 3.

In FIG. 2, dissolution profiles are provided for all of TU formulations51, 53 and 55 (Table 20); Formulation 9 (Table 2), and Capsules 2 and 4of Example 1 from US2010/0173882. The data were obtained in adissolution medium incorporating 2% TritonX-100 as a surfactant in theUSP 2 apparatus in accordance with the present invention.

In FIG. 3, dissolution profiles are provided for all of TU Formulations17 (Table 5), 28 (Table 10), 39 (Table 14), 56, 57 (Table 27) and 58(Table 21). The data were obtained in a dissolution medium incorporating2% TritonX-100 as a surfactant in the USP 2 apparatus in accordance withthe present invention.

TABLE 21 Formulation # 58 Ingredient Composition (% w/w) TU 120 mg/gm OA30.05 GMO 18.97 Labrafil M 1944 CS 14.71 Cremophor RH40 11.44 Tween 8022.87 Phytosterol Saturated Lecithin 0.98 HPMC 0.98 MicrocrystallineCellulose 40 parts of microcrystalline cellulose were added to 60 partsof the above formulation.

EXAMPLE 3 Preparation of Compositions Comprising TestosteroneUndecanoate and Phytosterols

The percentage of phytosterol in the phytosterol-saturated formulationsranges from 2% to 20%. Three formulations are described in Table 22containing between 5.8% and 44.6% phytosterols. FIG. 4 describes thedissolution profiles of these three formulations. Dissolution wasmeasured in 900 mL of 25 mM phosphate buffer at pH 7.0 containing 0.1%SLS, obtained at 200 rpm using USP 2 apparatus. Formulation 59illustrates the dissolution of a formulation with the properties ofremaining a liquid a room temperature, while Formulation 60 is asuitable formulation which is solid at room temperature. Phytosterols inexcess of the amount soluble at 70° C. may be added to the compositionto modulate the release rate, as illustrated by the dissolution profileof Formulation 61 in FIG. 4. Formulation 61 further has the desirableproperty of being a sufficiently hard material that it may be reduced toa powder, which is fillable into a capsule by ordinary means. As can beseen from FIG. 4, phytosterols behave as delayed release agents due totheir high log P (˜12) and hydrophobic properties.

The formulations of Table 22 range in phytosterol composition from about6% to 45% by weight. The same formulations range in TU composition fromabout 20% to about 72% by weight.

TABLE 22 Formulation compositions with phytosterols Percent compositionComponent Formulation 59 Formulation 60 Formulation 61 TU 20.3% 71.7%42.2% Oleic acid 18.5% 6.7% 4.0% GMO 11.1% 4.0% 2.4% Labrafil M 1944 CS8.4% 3.1% 1.8% Cremophor RH40 7.1% 2.6% 1.5% Tween 80 14.1% 5.1% 3.0%Phytosterols 18.2% 5.8% 44.6% Lyso Lecithin 0.6% 0.2% 0.1% HPMC 0.6%0.2% 0.1% Vitamin E 1.3% 0.5% 0.3%

EXAMPLE 4 In Vivo Dosing and PK Profile of Testosterone Undecanoate inLipid Formulations

A test was conducted of TU-containing lipid formulations for increasedabsorption in accordance with the methods of Shackleford et al., J.Pharmacol. And Exptl. Therap., 2003, vol. 306, no. 3, pp. 925-933.

Test formulations were administered to four beagle dogs (body weight8-10 kg) with food. The dosages were delivered as formulationsconsisting of two or three capsules. There were six differentformulations in this study and they were identified by letters A throughF.

Treatment A was a reference formulation of testosterone undecanoate (40mg TU in a vehicle of 60:40 castor oil:lauroglycol, which is theformulation of the commercial product Andriol Testocap®). Treatments Bthrough F all contained TU in castor oil base (Formulation 52 in Table20) and are described in Table 23. All treatments, including thereference formulation contained a dosage of 80 mg per dog of TU, and onetreatment also contained 100 mg of testosterone (T).

Whole venous blood samples of approximately 2.0 mL were collected from aperipheral vein of all animals for determination of serum concentrationsof the reference or test article. Samples were collected at thefollowing target time points at each dose: predose, 0.25, 0.5, 1, 2, 4,6, 8 and 12 hours after administration.

Graphs of the results of serum concentration analyses for TU and T areprovided in FIG. 5. It can be seen from FIG. 5 that significant TUabsorption was observed with Formulation C (TU+castor oil+solubilizedphytosterols+solid phytosterols), Formulation B (TU+castoroil+solubilized phytosterols) and Formulation D (TU+castoroil+solubilized phytosterols+phytosterols esters), as compared toreference Formulation A, lacking phytosterols.

The TU and T area under the curve (AUC) results and relativebioavailability were as follows:

TABLE 23 PK parameters from a formulation study in beagle dogs Mean TURelative Mean T Relative Treatment exposure, Standard bioavailabilityexposure, Standard bioavailability description ng*h/mL Deviation (TU)ng*h/mL Deviation (T) A 80 mg TU in a 1029.9 349.2 100% 65.6 16 100%formulation of 60:40 castor oil:lauroglycol B 80 mg TU as 1437.8 454.9140% 83.9 21 128% Formulation 52 C 80 mg TU as 2181.5 1124.0 212% 99.720.7 152% Formulation 52, co- dosed with 400 mg phytosterols D 80 mg TUas 1357.5 829.6 132% 62.1 19.8  95% Formulation 52, co- dosed with 640mg phytosterol esters E 80 mg TU as 1297.5 214.1 126% 143 48.1 218%Formulation 52, 100 mg of testosterone, 640 mg phytosterol esters F 80mg TU as 1700.0 867.8 165% 76.4 13.4 116% Formulation 52, 5 mgfinasteride

This example demonstrates that the formulations of the present inventionincrease the absorption of TU up to 2-fold, as compared to a commercialformulation. The resulting T exposures are also increased.

EXAMPLE 5 In Vivo Dosing and Pk Profile of Testosterone Undecanoate inLipid Formulations

This study consisted of two parts: Part 1 and Part 2. Part 1 of thestudy examined the effects of the metabolic inhibitors dutasteride andfinasteride, and Part 2 examined the effect of 800 mg of phytosterols onT and DHT.

Part 1 consisted of two arms: a dutasteride arm and a finasteride arm.In the dutasteride arm four female Beagle dogs were dosed with 80 mgtestosterone undecanoate (#52) and 400 mg phytosterol powder for threedays (Days 3-5) followed by dutasteride at 2.5 mg (a one day loadingdose; Day 6) and dutasteride at 0.5 mg for three more days (Days 7-9).These dogs then received 80 mg testosterone undecanoate (#52), 400 mgphytosterol powder, and 0.5 mg dutasteride for three days (days 10-12).The finasteride arm (four female Beagle dogs) was dosed identically tothe dutasteride arm except finasteride at 5.0 mg was given instead ofdutasteride, and the study lasted an additional three days (Days 13-15),during which 400 mg phytosterol only was dosed the first two days (Days13, 14), and 80 mg TU in oleic acid formulation (#54) plus 400 mgphytosterols were dosed on Day 15. All testosterone undecanoate doseswere administered to animals in the fed state.

Part 2 consisted of one arm and four female Beagle dogs were dosed with80 mg testosterone undecanoate and 800 mg phytosterol powder for oneday. All doses of testosterone undecanoate were administered to animalsin the fed state.

Whole venous blood samples of approximately 2.0 mL were collected from aperipheral vein of all animals for determination of serum concentrationsof T and DHT by LCMS. Samples were collected at the following targettime points at each dose: predose, 0.25, 0.5, 1, 2, 4, 6, 8 and 12 hoursafter administration.

Graphs of the results of serum concentration analyses for testosteroneare provided in FIG. 6. It can be seen from FIG. 6 that significantsystemic T exposure was observed with the oleic acid formulation (#54)relative to the Castor oil formulation (#52). The DHT levels with theOleic acid formulation were also significantly lower relative to theCastor oil formulation (#52) as shown in FIG. 10.

Graphs of the results of serum concentration analyses for T and DHT forthe finasteride arm and the dutasteride arm are provided in FIGS. 7 & 8,respectively. It can be seen from FIGS. 7 & 8 that 5-alpha-reductaseinhibitors had no significant effect on the T and DHT exposures.

Graphs of the results of serum concentration analyses for testosteronefor Part 2 evaluating the effect of 800 mg of phytosterol vs. 400 mg inPart 1 using the castor oil formulation (#52) are provided in FIG. 9. Itcan be seen from FIG. 9 that there was no difference in T levels withincreased levels of phytosterols.

Bar graphs of average T and DHT exposures (ng-h/mL) for all sixtreatments of TU formulations in beagle dogs in this study are given inFIG. 10. All treatments were co-dosed with 400 mg phytosterols excepttreatment L which was co-dosed with 800 mg of phytosterols. Error barsrepresent plus and minus one standard deviation.

It can be seen from FIG. 10 that oleic acid formulation gives thehighest T level and lowest DHT level of all the treatments tested. TheDHT/T ratio for this formulation is approaching the normal DHT/T valueof 0.17 to 0.26 (FIG. 11). The numerical data for TU and T exposure andrelative bioavailabilities for this study is given in Table 24 below.

TABLE 24 PK parameters from a formulation study in beagle dogs Mean TURelative Mean T Relative exposure, Standard bioavailability exposure,Standard bioavailability DHT/T Treatment description ng*h/mL DeviationTU² ng*h/mL Deviation (T)² ratio G and I: Formulation 52  3110¹  947¹302% 123.6¹ 16.4¹ 188% 0.49 80 mg TU in a castor oil formulation,co-dosed with 400 mg phytosterols K Formulation 54 3030 474 294% 21018.4 320% 0.26 80 mg TU in an oleic acid formulation, co-dosed with 400mg phytosterols H Formulation 52 2680 989 260% 132 27.9 201% 0.77 80 mgTU in a castor oil formulation, co-dosed with 400 mg phytosterols,co-dosed with 0.5 mg dutasteride J: Formulation 52 1660 342 161% 11533.5 175% 0.56 80 mg TU in a castor oil formulation, co-dosed with 400mg phytosterols, co-dosed with 5 mg finasteride L: Formulation 52 2630969 255% 138 30.6 210% 0.27 80 mg TU in a castor oil formulation,co-dosed with 800 mg phytosterols ¹The mean values for Formulation 52co-dosed with 400 mg phytosterols reflect the average of two groups of 4beagle dogs (Treatments G and I). ²Referenced to the TU and T exposuresof Treatment A, Table 23.

This example demonstrates that formulations of the present inventionenhance TU absorption relative to the reference formulation (Treatment Aof Table 23) by up to 3-fold. This example also demonstrates thatresulting T exposures are increased up to 3-fold relative to the samereference formulation. It is also observed that the DHT/T ratios forTreatment K and L approach the normal physiological values in humans,versus other formulations.

EXAMPLE 6 Lipid Dispersion Studies

The lipid dispersion test can be used to select formulations thatmaximize the amount of TU in the aqueous phase.

Buffer solution (100 mL) is prepared. Each test requires 36 mL with thefollowing composition: 50 mM TRIS maleate/150 mM NaCl/5 mM CaCl₂.2H₂O/5mM Na taurodeoxycholate/1.25 mM lecithin.

TRIS, maleic acid, NaCl and CaCl₂.2H₂O are dissolved together. Thebuffer can be made to about 90% final volume, with adjustment of the pHto 6.8 with NaOH or HCl. Na taurodeoxycholate is dissolved into thesolution. Lipoid E PC S should be removed from the freezer and allowedto thaw to room temperature in its bag with desiccant before removing itfrom the bag. Lecithin is dissolved, which requires stirring for severalhours for the solution to clarify. The solution is quantitativelytransferred back into a volumetric flask and diluted to volume withpurified water. The final pH is checked and recorded it on the flask.Once the solution is made, it is stored in the refrigerator.

TABLE 25 Dispersion media MW Molarity Wt (g) to Wt (g) to Component(g/mol) (M) make 100 mL make 500 mL TRIS (base) 121.14 0.05 0.60573.0285 Maleic acid 116.08 0.05 0.5804 2.902 NaCl 58.44 0.15 0.8766 4.383CaCl2—2H20 147.02 0.005 0.07351 0.36755 Na 521.7 0.005 0.26085 1.30425taurodeoxycholate (hydrate) Lecithin 775 0.00125 0.096875 0.484375(Lipoid E PC S)Dispersion Experiment

Procedure: To the 36 mL of the dispersion buffer add 0.2 mL offormulation (initial test will use vehicle blank) quantitatively. Notethat 0.2 mL per 40 mL is equivalent to about 1 mL in 200 mL, so it is abiorelevant amount. Draw samples every 15 minute to assess dissolutionover 60 min; analyze for TU.

The results are presented in Table 26 below. The improved dispersionproperties of the invention are evident in the percentage of TUsolubilized. The Castor oil:lauroglycol formulation is the samecomposition as Andriol® Testocaps®.

TABLE 26 Results of dispersion testing of 60 mg of TU in Formulation 52and castor oil:lauroglycol 60:40 Formulation TU percent contained indispersed phase Castor oil:lauroglycol 60:40   0% Formulation 52 84.5%

EXAMPLE 7 Stability of Compositions Comprising Testosterone Undecanoate

The following formulations were stored at 60° C. for up to 2 weeks. TheIodine values for the formulations 56 and 57 were measured at 0, 1, and2 weeks to assess the stability of the unsaturated excipients in theformulation, in the presence and absence of phytosterols.

TABLE 27 Formulation # 56 57 Ingredient Composition (% w/w) TU 120 mg/gm120 mg/gm OA 30.05 30.05 GMO 18.97 18.97 Labrafil M 1944 CS 14.71 14.71Cremophor RH40 11.44 11.44 Tween 80 22.87 22.87 Phytosterol 0 Saturated*Lecithin 0.98 0.98 HPMC 0.98 0.98 *Component percentages are takenbefore saturation of the vehicle with phytosterols at 70° C.

The iodine value I_(I) is the number that expresses in grams thequantity of halogen, calculated as iodine, that can be fixed in theprescribed conditions by 100 g of the substance. Iodine value test perUSP <401> Fats and Fixed Oils (Method 1) is used for determining theIodine number. The method follows.

Procedure: Introduce the prescribed quantity of the substance to beexamined (mg) into a 250 ml flask fitted with a ground-glass stopper andpreviously dried or rinsed with glacial acetic acid, and dissolve it in15 ml of chloroform unless otherwise prescribed. Add very slowly 25.0 mlof iodine bromide solution. Close the flask and keep it in the dark for30 min unless otherwise prescribed, shaking frequently. Add 10 ml of a100 g/l solution of potassium iodide and 100 ml of water. Titrate with0.1 M sodium thiosulphate, shaking vigorously until the yellow color isalmost discharged. Add 5 ml of starch solution and continue thetitration adding the 0.1 M sodium thiosulphate dropwise until the coloris discharged (n₁ ml of 0.1 M sodium thiosulphate). Carry out a blanktest under the same conditions (n₂ ml of 0.1 M sodium thiosulphate).

$I_{1} = \frac{1.269\left( {n_{2} - n_{1}} \right)}{m}$

Iodine number values after 1 and 2 weeks are given in Table 28. It canbe seen from Table 28 that phytosterols minimize the degradation of theoxidation of the double bonds in the lipid-based formulations. Thisdiscovery enables longer shelf-life for oxidation-prone lipid-basedformulations to be achieved.

TABLE 28 Stability results Iodine Test Formulation Initial 1 week at 60°C. 2 weeks at 60° C. 56 59.48 42.89 41.86 57 59.20 57.24 53.26

The clinical formulations 51, 53, and 55 the compositions of which arelisted in Table 20 were stored at 25° C./60RH for 4 weeks. The TUcontent and impurities were measured at 0, and 4 weeks. Results at 0 and4 weeks are given in Table 29.

TABLE 29 Stability results Initial 4 weeks at 25° C./60RH Formulation(related imps) (related imps) 51 101.8% (0.23) 99.6% (0.50) 53 100.4%(0.43) 98.7% (1.11) 55 101.8% (0.45) 98.5% (0.92)

The results in Table 28 demonstrate that phytosterols enhance thestability of formulations containing unsaturated fatty acids orglycerides. Table 29 demonstrates the acceptable stability of theclinical formulations 51, 53, and 55 (Table 20).

EXAMPLE 8 In-Vivo Dosing and Prediction of Human PK Parameters ofCompositions Comprising Testosterone Undecanoate

Formulations 51, 53, and 55 were selected for assessment of PK profilein hypogonadal men. These capsules were manufactured according toExample 2, each capsule containing 40 mg of TU. Using acceptedprinciples of allometric scaling and the direct comparison of thein-vivo results obtained with Andriol® Testocaps®, human clinicalexposures are predicted as in Tables 30 and 31.

A randomized, single-dose, open-label, 5-period crossover study toevaluate the bioavailability, safety, and tolerability of four differenttestosterone undecanoate treatments versus a reference formulation(Andriol® Testocaps®) that is the current marketed formulation of TU wasperformed. Three investigational formulations 51, 53, and 55 comprisedthree of the treatments; the fourth treatment was a combination of thetwo (Formulations 53 and 55) of the investigational formulations. Thestudy enrolled hypogonadal men that have low systemic testosteronelevels but do not exhibit clinical symptoms at such levels (i.e., thesubjects are asymptomatic).

A total of 8 subjects were enrolled to receive a single dose of each ofthe four test treatments (80 mg TU per dose) and the referenceformulation (80 mg TU as Andriol® Testocaps®) under fed conditions incrossover fashion. Subjects were randomized to treatment sequence with awashout period of 24 hours (period 1 to 3 for Andriol® Testocaps®,formulation 51 and 53) or 48 hours (period 4 and 5 for formulations 55and 53+55) between each blinded administration of study drug. Each doseof study drug was immediately preceded by a standard meal to allow fordosing in the fed state.

Serial blood samples for serum PK analysis of testosterone anddihydrotestosterone (DHT) levels were collected at 0 (pre-dose), 0.5, 1,2, 3, 4, 5, 6, 8, 10, 12, 14, 24 and additional 16 and 48 (period 4 and5) hours after dosing of each of the test and reference TU formulationsto characterize single-dose bioavailability and pharmacokinetics. Vitalssigns, AEs, clinical labs, ECGs, and urinalysis was assessed pre-doseand at various times through discharge.

Based on the dog PK data on Andriol® Testocaps® and formulations 52 and54 and available human data on Andriol® Testocaps®, the predicted humanCavg for formulations 51 and 53 is given in Tables 30 and 31. Note thatFormulations 51 and 53 are derived from Formulations 52 and 54 byaddition of minor amounts of antioxidants. For comparison, the steadystate testosterone C_(avg) of a SEDDS formulation from ClarusTherapeutics with a dose of 316 mg of TU (200 mg T equivalent) is 514ng/dL (Roth et al, International Journal of Andrology, on-line issueOctober 2010).

Allometric scaling was carried out using the published method containedin guidance published by the Food and Drug Administration of the UnitedStates (FDA), in Guidance for Industry: Estimating the Maximum SafeStarting Dose in Initial Clinical Trials for Therapeutics in AdultHealthy Volunteers, published in July 2005. The factor of 0.54 is usedto convert from mg/kg dosing in dogs to the approximate equivalent dosein humans. In the in-vivo study in beagle dogs, the TU dose was 80 mg,the average animal weight 9.4 kg, and the dose/kg body weight is 8.5mg/kg. The equivalent human dose is 8.5 mg/kg X 0.54=4.6 mg/kg. For aproposed human dose of 80 mg, and an average adult male weight of 60 kg,the dose/kg body weight would be 1.3 mg/kg. Assuming linearpharmacokinetics for T-exposure resulting from the dosing of TU, theresulting predicted human exposure factor for the 80 mg human dose is(1.3/4.6)=0.28.

TABLE 30 Predicted human PK parameters for testosterone for Formulations52 and 54 by allometric scaling AUC (0-12) Formulation (ng-h/mL)Formulation 52 result in dogs 99.7 Predicted human PK 27.9 parameter ofFormulation 51 Formulation 54 result in dogs 210 Predicted human PK 58.8parameter of Formulation 53

A direct comparison of the T exposure (C_(max) and AUC) between dogs andhumans is also possible based on published data for Andriol® Testocaps®(Bagchus et al). The resulting predicted values of the AUC (0-12 hr)exposure is somewhat higher than the allometric approach using thedirect comparison approach.

TABLE 31 Predicted human PK parameters for 80 mg TU dose forFormulations 52 and 54 by direct comparison method Composition or CmaxAUC 0-12 hrs formulation ng/mL ng-h/mL Dog: 60:40 castor 7.7¹ 35.6¹oil:lauroglycol FCC Human: 60:40 castor 32.9² 65.6² oil:lauroglycol FCCRatio dog:human: 0.23 0.54 Formulation 52 result in 53.6 99.7 dogsPredicted human PK 12.5 54.1 parameters of Formulation 51³ Formulation54 result in 123 210 dogs Predicted human PK 28.8 113.4 parameters ofFormulation 53³ ¹Treatment in beagle dogs is the same composition aspublished for Andriol ® Testocaps ® except filled into hard gelatincapsules. ²Testocaps ® from Andriol ® Testocaps ® web site, W M Bagchus,F Maris, P G Schnabel, N S Houwing, Dose Proportionality of Andriol ®Testocaps ™) ³Phytosterols, 400 mg, co-administered with Formulations 52and 54 to dogs. ⁴Formulations 51 and 53 will be co-administered inhumans with phytosterols, 400 mg.

FIG. 12 shows the predicted average human concentrations of T and DHTresulting from dosing with Formulations 51 and 53. Treatment I isFormulation 51 co-dosed with 400 mg phytosterols. Treatment K isFormulation 53 co-dosed with 400 mg phytosterols. Treatment L isFormulation 51 co-dosed with 800 mg phytosterols. The predictions ofhuman exposure are based on extrapolation of in vivo results in beagledogs, using the beagle dog and human PK parameters for a referenceformulation of TU in 60% castor oil and 40% lauroglycol.

While the invention has been described herein in reference to specificaspects, features and illustrative embodiments of the invention, it willbe appreciated that the utility of the invention is not thus limited,but rather extends to and encompasses numerous other variations,modifications and alternative embodiments, as will suggest themselves tothose of ordinary skill in the field of the present invention, based onthe disclosure herein. Correspondingly, the invention as hereinafterclaimed is intended to be broadly construed and interpreted, asincluding all such variations, modifications and alternativeembodiments, within its spirit and scope.

What is claimed is:
 1. A method of treating male hypogonadism in asubject in need thereof, the method comprising administering to thesubject an oral formulation comprising: a) testosterone undecanoate; b)from about 10% to about 90% by weight of a non-sterol solubilizing agenteffective for solubilization of the testosterone undecanoate; and c)from about 2% to about 45% by weight of a mixture of phytosterols orphytosterol esters, wherein the mixture comprises from 40% to 58% byweight of beta-sitosterol or esters thereof; from 20% to 30% by weightof campesterol or esters thereof; from 14% to 22% by weight stigmasterolor esters thereof; from 0 to 6% by weight brassicasterol or estersthereof; from 0 to 5% by weight sitostanol or esters thereof; and from 0mg/g to 15 mg/g tocopherols; wherein the phytosterols or phytosterolesters provide increased plasma levels of testosterone following oraladministration in comparison to the plasma levels of testosteroneproduced following oral administration of testosterone undecanoate in aformulation free of phytosterols and phytosterol esters.
 2. The methodof claim 1, wherein the oral formulation comprises from 40 to 400 mg oftestosterone undecanoate.
 3. The method of claim 1, wherein the oralformulation comprises from 0.1 to 40% by weight testosteroneundecanoate.
 4. The method of claim 1, wherein the oral formulationcomprises from about 12.5% to about 85% by weight non-sterolsolubilizing agent.
 5. The method of claim 1, wherein the non-sterolsolubilizing agent is selected from lipids, surfactants, and mixturesthereof.
 6. The method of claim 5, wherein the non-sterol solubilizingagent comprises an ester of a monohydric alcohol with an organic acid.7. The method of claim 1, wherein the non-sterol solubilizing agentcomprises propylene glycol monolaurate.
 8. The method of claim 1,wherein the non-sterol solubilizing agent comprises polyoxyl 40hydrogenated castor oil.
 9. The method of claim 1, wherein the oralformulation comprises: a) from 0.1 to 40% by weight testosteroneundecanoate; b) from about 10% to about 90% by weight the non-sterolsolubilizing agent effective for solubilization of the testosteroneundecanoate; and c) from about 2% to about 45% by weight the mixture ofphytosterols or phytosterol esters, wherein the mixture comprises from40% to 58% by weight of beta-sitosterol or esters thereof; from 20% to30% by weight of campesterol or esters thereof; from 14% to 22% byweight stigmasterol or esters thereof; from 0 to 6% by weightbrassicasterol or esters thereof; from 0 to 5% by weight sitostanol oresters thereof; and from 0 mg/g to 15 mg/g tocopherols.
 10. The methodof claim 9, wherein the oral formulation comprises from 12.5 to 85% byweight non-sterol solubilizing agent.
 11. The method of claim 9, whereinthe non-sterol solubilizing agent comprises propylene glycolmonolaurate.
 12. The method of claim 9, wherein the non-sterolsolubilizing agent comprises polyoxyl 40 hydrogenated castor oil. 13.The method of claim 9, wherein the oral formulation is self-emulsifyingor self-microemulsifying.
 14. The method of claim 9, wherein theformulation further comprises alpha-tocopherol or alpha-tocopherolacetate.